Distance protection method for new energy power transmission line

Abstract

The invention relates to the technical field of power system relay protection, in particular to a distance protection method for a new energy power transmission line, and the method comprises the steps: obtaining a first virtual potential corresponding to a fault line at a first moment; corresponding fault voltage and fault current of the fault line at a second moment are obtained, and the second moment is after the first moment and is separated from the first moment by a preset time interval. And determining a first voltage drop angle according to the first virtual potential, the fault voltage and the fault current, wherein the first voltage drop angle is used for representing the voltage drop between the fault voltage and the first virtual potential and the angle difference between the voltage drop of the fault current and the voltage drop of the setting impedance. And determining a first phase comparison angle according to the fault voltage, the fault current and the setting impedance. And determining a fault type of the line protection device according to the first voltage drop angle, the first phase comparison angle and a preset angle range, wherein the fault type comprises an internal fault and an external fault. The method can improve the accuracy of fault type discrimination, and improves the operation stability of a power system.

Description

Technical Field

[0001] The present application relates to the technical field of relay protection for power systems, and in particular to a distance protection method for a new energy power transmission line. Background Art

[0002] In power systems, distance protection is a commonly used fault protection method. When a short circuit occurs in a line, the voltage and current corresponding to the faulty line will change at the same time. Based on this feature, distance protection can judge the scope of the fault through the ratio of voltage to current (i.e. impedance), thereby cutting off the fault to ensure the safe and stable operation of the power system.

[0003] Distance protection can only protect against positive faults in the line. Positive faults refer to faults in which the direction of the fault current is consistent with the direction of the power supply. When a reverse fault occurs in the line (a fault in which the direction of the fault current is opposite to the direction of the power supply), the distance protection will not operate.

[0004] Since new energy power generation systems (such as wind power, solar power generation, etc.) contain controllable power electronic devices. When a line fails, the new energy control strategy will regulate the power output of the new energy power generation system to ensure the stable operation and efficient power generation of the system. However, this control strategy will affect the current of the output line, and the distance protection cannot judge the scope of the fault by the ratio of voltage to current, that is, it cannot determine whether the current fault is a forward direction fault or a reverse direction fault. As a result, the fault judgment accuracy of the existing new energy power generation system is low, and the stability of the power system operation is threatened. Summary of the invention

[0005] The present application provides a distance protection method, device, electronic device and computer-readable storage medium for a new energy transmission line, which can improve the accuracy of fault type identification, thereby improving the stability of power system operation.

[0006] In a first aspect, the present application provides a distance protection method for a new energy transmission line, which can improve the accuracy of fault type identification and improve the stability of power system operation.

[0007] In the first aspect, the present application provides a distance protection method for a new energy transmission line, which is applied to a line protection device, and the line protection device is used to monitor the line status of a multi-phase line. The method includes: obtaining a first virtual potential corresponding to the fault line at a first moment, and the fault line is a line in the multi-phase line where a fault occurs. Obtain the fault voltage and fault current corresponding to the fault line at a second moment, the second moment is after the first moment, and the second moment and the first moment are separated by a preset time interval. Determine a first voltage drop angle based on the first virtual potential, the fault voltage, and the fault current, and the first voltage drop angle is used to characterize the voltage drop between the fault voltage and the first virtual potential, and the angle difference between the voltage drop of the fault current and the set impedance. Determine a first phase angle based on the fault voltage, the fault current, and the set impedance. Determine the fault category of the line protection device based on the first voltage drop angle, the first phase angle, and the preset angle range, and the fault category includes an in-zone fault and an out-of-zone fault.

[0008] In some embodiments, obtaining the first virtual potential corresponding to the fault line includes: obtaining multiple first voltages and multiple first currents corresponding to the multi-phase line at the first moment, and the multiple first voltages, multiple first currents and the multi-phase line correspond one to one. According to the multiple first voltages and multiple first currents, the active power of the line protection device is determined. If the active power is greater than 0, the first virtual potential is determined according to the target first voltage, the target first current and the first potential coefficient, the target first voltage is the voltage corresponding to the fault line among the multiple first voltages, the target first current is the current corresponding to the target first voltage among the multiple first currents, the first virtual potential is positively correlated with the target first voltage, and the first virtual potential is negatively correlated with the target first current. If the active power is less than or equal to 0, the first virtual potential is determined according to the target first voltage, the target first current and the second potential coefficient, the first virtual potential is positively correlated with the target first voltage, the first virtual potential is positively correlated with the target first current, and the first potential coefficient is greater than the second potential coefficient.

[0009] In some embodiments, the active power of the line protection device is determined based on multiple first voltages and multiple first currents, including: obtaining multiple phase differences, the multiple first voltages, the multiple first currents, and the multiple phase differences correspond one to one, the first phase difference is the difference between the phase of any one of the multiple first voltages and the phase of a corresponding current of the multiple first currents, and the first phase difference is one of the multiple phase differences.

[0010] Active power is determined based on the plurality of first voltages, the plurality of first currents, and the plurality of phase differences.

[0011] In some embodiments, obtaining a fault voltage and a fault current corresponding to the fault line at the second moment includes: obtaining a plurality of second voltages and a plurality of second currents corresponding to the multi-phase line at the second moment, wherein the plurality of second voltages, the plurality of second currents and the multi-phase line correspond one to one. Determining the fault line according to the plurality of second voltages and the plurality of second currents. Determining the fault line according to the fault line, wherein the fault voltage is a voltage corresponding to the fault line among the plurality of second voltages, and the fault current is positively correlated with a current corresponding to the fault line among the plurality of second currents.

[0012] In some embodiments, the multiple first voltages are multiple phase voltages corresponding to the multi-phase line, the multiple first currents are multiple phase currents corresponding to the multi-phase line, the multiple second voltages are multiple phase voltages corresponding to the multi-phase line, and the multiple second currents are multiple phase currents corresponding to the multi-phase line. Or, the multiple first voltages are multiple line voltages corresponding to the multi-phase line, the multiple first currents are multiple line currents corresponding to the multi-phase line, the multiple second voltages are multiple line voltages corresponding to the multi-phase line, and the multiple second currents are multiple line currents corresponding to the multi-phase line.

[0013] In some embodiments, if the active power is greater than 0, the line protection device is a power generation side line protection device, the preset angle range includes a first preset angle range, a second preset angle range and a third preset angle range, and the fault category is determined according to the first voltage drop angle, the first phase angle and the preset angle range, including: if the first voltage drop angle is within the first preset angle range, and the first phase angle is within the second preset angle range, then the fault category is determined to be an intra-zone fault. If the first voltage drop angle is not within the first preset angle range, and the first phase angle is within the third preset angle range, then the fault category is determined to be an intra-zone fault, the second preset angle range is a sub-range of the third preset angle range, the maximum value of the third preset angle range is greater than the maximum value of the second preset angle range, and the minimum value of the third preset angle range is less than the minimum value of the second preset angle range.

[0014] In some embodiments, if the active power is less than or equal to 0, the line protection device is a receiving-side line protection device, the preset angle range also includes a fourth preset angle range, and the fault category is determined according to the first voltage drop angle, the first phase angle, and the preset angle range, including: if the first voltage drop angle is within the fourth preset angle range, and the first phase angle is within the third preset angle range, then the fault category is determined to be an intra-zone fault. If the first voltage drop angle is not within the fourth preset angle range, and the first phase angle is within the second preset angle range, then the fault category is determined to be an intra-zone fault, there is no overlapping angle between the first preset angle range and the fourth preset angle range, the maximum value of the first preset angle range is 180° away from the maximum value of the fourth preset angle range, and the minimum value of the first preset angle range is 180° away from the minimum value of the fourth preset angle range.

[0015] In some embodiments, after determining the fault category of the line protection device based on the first voltage drop angle, the first phase angle and the preset angle range, the method also includes: if the fault category is an intra-zone fault, issuing a first cut-off instruction to the circuit breaker corresponding to the faulty line, and the first cut-off instruction is used to instruct the circuit breaker to trip.

[0016] In a second aspect, the present application provides a distance protection device for a new energy transmission line. The distance protection device for the new energy transmission line can be a line protection device. The line protection device is used to monitor the line status of a multi-phase line, and includes an acquisition module and a determination module.

[0017] The acquisition module is used to acquire a first virtual potential corresponding to a faulty line at a first moment, wherein the faulty line is a line in which a fault occurs in a multi-phase line.

[0018] The acquisition module is also used to acquire the fault voltage and fault current corresponding to the fault line at a second moment, where the second moment is after the first moment and there is a preset time interval between the second moment and the first moment.

[0019] A determination module is used to determine a first voltage drop angle according to a first virtual potential, a fault voltage and a fault current, wherein the first voltage drop angle is used to characterize the angle difference between the voltage drop between the fault voltage and the first virtual potential and the voltage drop between the fault current and the set impedance.

[0020] The determination module is also used to determine the first phase angle according to the fault voltage, the fault current and the setting impedance.

[0021] The determination module is further used to determine the fault category of the line protection device according to the first voltage drop angle, the first phase comparison angle and the preset angle range, and the fault category includes an in-zone fault and an out-of-zone fault.

[0022] In a third aspect, the present application provides an electronic device, comprising a processor and a memory, wherein the processor is configured to execute a computer program stored in the memory to implement a method as described in any one of the first aspects above.

[0023] In a fourth aspect, the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the method as described in any one of the first aspects above.

[0024] In the technical solution provided by the present application, the line protection device can obtain the first virtual potential corresponding to the fault line at the first moment, and the fault line is the line where the fault occurs in the multi-phase line. And obtain the fault voltage and fault current corresponding to the fault line at the second moment, the second moment is after the first moment, and the second moment and the first moment are separated by a preset time interval. And determine the first voltage drop angle according to the first virtual potential, the fault voltage and the fault current, and the first voltage drop angle is used to characterize the voltage drop between the fault voltage and the first virtual potential, and the angle difference between the voltage drop of the fault current and the set impedance. And determine the first phase angle according to the fault voltage, the fault current and the set impedance. Finally, the fault category of the line protection device is determined according to the first voltage drop angle, the first phase angle and the preset angle range. The fault category includes in-zone faults and out-of-zone faults, which can improve the accuracy of fault category identification and improve the stability of power system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 This is a schematic diagram of an application scenario of a distance protection method for a new energy transmission line provided in an embodiment of the present application;

[0027] Figure 2 It is a flow chart of a distance protection method for a new energy transmission line provided in an embodiment of the present application;

[0028] Figure 3 It is a line schematic diagram of a distance protection method for a new energy transmission line provided in an embodiment of the present application;

[0029] Figure 4 It is another flow chart of a distance protection method for a new energy transmission line provided in an embodiment of the present application;

[0030] Figure 5 It is a schematic diagram of a reverse fault voltage drop angle of a distance protection method for a new energy transmission line provided in an embodiment of the present application;

[0031] Figure 6 This is another flow chart of a distance protection method for a new energy transmission line provided in an embodiment of the present application;

[0032] Figure 7 It is a schematic diagram of a positive direction fault voltage drop angle of a distance protection method for a new energy transmission line provided in an embodiment of the present application;

[0033] Figure 8 It is a schematic diagram of a distance protection device for a new energy transmission line provided in an embodiment of the present application;

[0034] Fig. 9 It is a schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0036] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0037] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0038] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0039] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0040] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0041] The renewable energy power generation system can deliver electric energy to the grid through the grid-connected transmission circuit. Distance protection is a common fault protection method for renewable energy power generation systems. When a positive fault occurs on the line (it may be an internal fault or an external fault) and the fault point is within the range of the distance protection setting point, the line protection device determines that there is an internal fault and instructs the circuit breaker corresponding to the faulty line to trip, thereby cutting off the fault. When a reverse fault occurs on the line, the line protection device does not operate.

[0042] When a short circuit occurs in a line, the voltage and current corresponding to the faulty line will change at the same time. Traditional distance protection schemes, such as phase-comparison distance protection, can judge the scope of the fault based on this feature by the ratio of voltage to current (i.e. impedance). When it is determined that a positive fault occurs in the line and the fault point is within the range of the distance protection setting point, the line protection device can cut off the fault to ensure the safe and stable operation of the power system.

[0043] Distance protection can only protect against positive faults in the line. Positive faults refer to faults in which the direction of the fault current is consistent with the direction of the power supply. When a reverse fault occurs in the line (a fault in which the direction of the fault current is opposite to the direction of the power supply), the distance protection will not operate.

[0044] like Figure 1 As shown, the positive direction fault is as follows Figure 1 The reverse direction fault can be Figure 1 F2 fault point and F3 fault point in.

[0045] Since the renewable energy power generation system contains controllable power electronic devices, when a line fault occurs, the renewable energy control strategy will regulate the power output of the renewable energy power generation system to ensure the stable operation and efficient power generation of the system. However, this control strategy will affect the current of the output line, and the traditional distance protection scheme cannot judge the scope of the fault by the ratio of voltage to current, that is, it cannot determine whether the current fault is a forward fault or a reverse fault. As a result, the fault judgment accuracy of the existing renewable energy power generation system is low, and the stability of the power system operation is threatened.

[0046] In view of this, an embodiment of the present application provides a distance protection method for a new energy transmission line, which can improve the accuracy of fault type identification and improve the stability of power system operation.

[0047] The technical solution of the embodiments of the present application is described below with reference to the examples in the accompanying drawings.

[0048] In the technical solution provided by the embodiment of the present application, the line protection device can obtain multiple phase voltages, multiple phase currents, multiple line voltages and multiple line currents corresponding to the multi-phase line in real time. The active power corresponding to the line protection device is calculated based on the multiple phase voltages, multiple phase currents, multiple line voltages and multiple line currents, and the multiple virtual potentials corresponding to the power generation side line protection device and the power receiving side line protection device are calculated based on the active power.

[0049] The line protection device calculates multiple virtual potentials according to multiple phase voltages, multiple phase currents, multiple line voltages and multiple line currents. The process can be as follows: Figure 2 As shown, including:

[0050] Step S201: Acquire a plurality of first voltages and a plurality of first currents corresponding to a multi-phase line at a first moment, wherein the plurality of first voltages, the plurality of first currents and the multi-phase line correspond one to one.

[0051] The line protection device can obtain multiple voltages and multiple currents in real time. The multiple voltages can be multiple first voltages or multiple second voltages. The multiple currents can be multiple first currents or multiple second currents. The multiple first voltages and multiple first currents are the multiple voltages and multiple currents obtained by the line protection device at the first moment, and the multiple second voltages and multiple second currents are the multiple voltages and multiple currents obtained by the line protection device at the second moment. The first moment is the moment before the second moment. The first moment and the second moment can be separated by a preset time interval. The preset time interval can be a positive integer multiple of the cycle time. For example, when the cycle time is 20ms, the preset time interval can be 100ms (5 times the cycle time). The present application does not limit the specific value of the preset time interval.

[0052] The multi-phase line may be a three-phase line of the power system, and the multiple first voltages and the multiple second voltages may be multiple phase voltages corresponding to the three-phase line, or multiple line voltages corresponding to the three-phase line. The multiple first currents and the multiple second currents may be multiple phase currents corresponding to the three-phase line, or multiple line currents corresponding to the three-phase line, which is not limited in this application.

[0053] For example, Figure 3 As shown, when the multi-phase lines are: A phase line, B phase line and C phase line, the multiple phase voltages can be: the voltage of the A phase line, the voltage of the B phase line and the voltage of the C phase line, respectively expressed as: U A , U B and U C The multiple phase currents can be: the current flowing through the load of the A phase line, the current flowing through the load of the B phase line, and the current flowing through the load of the C phase line, respectively expressed as: I A ,I B and I C The multiple line voltages can be: the voltage between the A phase line and the B phase line, the voltage between the B phase line and the C phase line, and the voltage between the C phase line and the A phase line, respectively expressed as: U AB , U BC and U CA The multiple line currents can be respectively: the difference between the current in the wire corresponding to the A phase line and the current in the wire corresponding to the B phase line, the difference between the current in the wire corresponding to the B phase line and the current in the wire corresponding to the C phase line, and the difference between the current in the wire corresponding to the C phase line and the current in the wire corresponding to the A phase line, which are respectively expressed as: I AB ,I BC and I CA .

[0054] The embodiment of the present application takes the case where multiple first voltages are multiple phase voltages and multiple first currents are multiple phase currents as an example to exemplarily illustrate the fault identification process. It can be understood that the fault identification process of multiple line voltages and multiple line currents has the same or similar calculation principle as the fault identification process of multiple phase voltages and multiple phase currents, and the present application will not elaborate on it here.

[0055] Step S202: determining the active power of the line protection device according to the multiple first voltages and the multiple first currents.

[0056] Exemplarily, the calculation formula of active power P may be:

[0057]

[0058] Among them, U A Indicates the voltage corresponding to the A phase line, U BIndicates the voltage corresponding to the B phase line, U C Indicates the voltage corresponding to the C phase line. A Indicates the current corresponding to phase A, I B Indicates the current corresponding to the B phase line, I C Indicates the current corresponding to the C phase line. Indicates the angle difference between the voltage corresponding to the A phase line and the current corresponding to the A phase line, Indicates the angle difference between the voltage corresponding to the B phase line and the current corresponding to the B phase line, Indicates the angle difference between the voltage corresponding to the C phase line and the current corresponding to the C phase line.

[0059] Step S203: judging whether the current line protection device is a power generation side line protection device or a power receiving side line protection device according to the active power.

[0060] When the renewable energy power generation system operates normally, the renewable energy power generation end generates active power, and the electric energy flows from the line protection device on the generating side to the line protection device on the receiving side. Therefore, the active power detected by the line protection device on the generating side is greater than 0. The active power detected by the line protection device on the receiving side is less than 0. When the active power generated by the renewable energy power generation end is 0, it means that the renewable energy is not generating electricity, that is, it can be considered that there is only the line protection device on the receiving side.

[0061] If the active power is greater than 0, the line protection device determines that the current device is a power generation side line protection device, and the line protection device executes step S204. If the active power is less than or equal to 0, the line protection device determines that the current device is a power receiving side line protection device, and the line protection device executes step S205.

[0062] Step S204: if the active power is greater than 0, determining a plurality of virtual potentials according to a plurality of first voltages, a plurality of first currents and a first potential coefficient.

[0063] If the active power is greater than 0, the line protection device determines that the current device is a generation side line protection device.

[0064] For example, when the active power is greater than 0, if the multi-phase lines are respectively A-phase line, B-phase line and C-phase line, the multiple virtual potentials may be respectively: the virtual potential V corresponding to the A-phase line A_1 , the virtual potential V corresponding to the B phase line B_1 The virtual potential V corresponding to the C phase line C_1 , virtual potential V A_1 , virtual potential V B_1 and virtual potential V C_1 The calculation formulas can be respectively:

[0065]

[0066] Among them, U A I represents the voltage corresponding to the A phase line, K1 represents the first potential coefficient, which is a constant, and K1 can be 1.1. A Indicates the current corresponding to phase A, Z L Indicates the impedance coefficient of the entire line length, which is a fixed value. B Indicates the voltage corresponding to the B phase line, I B Indicates the current corresponding to the B phase line, U C Indicates the voltage corresponding to the C phase line, I C Indicates the current corresponding to the C phase line.

[0067] Step S205: If the active power is less than or equal to 0, a plurality of virtual potentials are determined according to a plurality of first voltages, a plurality of first currents and a second potential coefficient.

[0068] If the active power is less than or equal to 0, the line protection device determines that the current device is a line protection device on the receiving side.

[0069] For example, when the active power is less than or equal to 0, if the multi-phase lines are respectively A-phase line, B-phase line and C-phase line, the multiple virtual potentials can be respectively: the virtual potential V corresponding to the A-phase line A_2 , the virtual potential V corresponding to the B phase line B_2 The virtual potential V corresponding to the C phase line C_2 , virtual potential V A_2 , virtual potential V B_2 and virtual potential V C_2 The calculation formulas can be respectively:

[0070]

[0071] Among them, U A represents the voltage corresponding to the A phase line, K2 represents the second potential coefficient, which is a constant, and K2 can be 0.1. A Indicates the current corresponding to phase A, Z L Indicates the impedance coefficient of the entire line length, which is a fixed value. B Indicates the voltage corresponding to the B phase line, I B Indicates the current corresponding to the B phase line, U C Indicates the voltage corresponding to the C phase line, I C Indicates the current corresponding to the C phase line.

[0072] It is understandable that the line protection device can obtain multiple first voltages and multiple first currents in real time, and determine the positive and negative of the active power according to the multiple first voltages and multiple first currents to determine whether the current device is a power generation side line protection device or a power receiving side line protection device. Both the power generation side line protection device and the power receiving side line protection device can calculate and store the corresponding multiple virtual potentials in real time.

[0073] After the power generation side line protection device and the power measurement line protection device calculate and store the multiple virtual potentials corresponding to the first moment according to the multiple first voltages and multiple first currents corresponding to the multi-phase line at the first moment, the power generation side line protection device and the power measurement line protection device can also obtain the multiple second voltages and multiple second currents corresponding to the multi-phase line at the second moment (the second moment is the moment after the first moment), and calculate and store the multiple virtual potentials corresponding to the second moment.

[0074] The method by which the power generation side line protection device and the power receiving line protection device calculate and store multiple virtual potentials corresponding to the second moment based on the multiple second voltages and multiple second currents corresponding to the multi-phase line at the second moment has the same or similar calculation principle as the above-mentioned steps S201 to S205, and is not elaborated in this application.

[0075] The line protection device on the power generation side / the line protection device on the power receiving side can detect in real time whether it is currently in a fault protection state. If it is in a fault protection state, the fault protection process is executed. If it is not in a fault protection state, the state of the current line protection device continues to be monitored and the fault protection process is not executed.

[0076] Embodiment 1.

[0077] The present application embodiment takes the current line protection device as a power generation side line protection device as an example to exemplify the process of the power generation side line protection device performing fault protection in the fault protection state. It is understandable that the power receiving side line protection device can also perform the fault protection process in the fault protection state.

[0078] The process of the line protection device on the generator side performing fault protection can be as follows: Figure 4 As shown, the following steps are included:

[0079] Step S401: obtaining a first virtual potential corresponding to a faulty line at a first moment, where the faulty line is a line in a multi-phase line where a fault occurs.

[0080] In the embodiment of the present application, the power generation side line protection device can determine the fault line from the multi-phase line by the current mutation amount within a preset time period and the voltage mutation amount within a preset time period. Other phase selection methods for determining the fault line can also be used, and the present application does not limit the phase selection method for the fault line.

[0081] The fault line can be a single-phase line, a two-phase line, or a three-phase line. For example, if the fault phase is a single-phase line, when the multi-phase lines are A-phase line, B-phase line, and C-phase line, the fault line can be A-phase line, B-phase line, or C-phase line. If the fault phase is two-phase, the fault line can be AB-phase line, BC-phase line, or CA-phase line. If the fault phase is three-phase, that is, when there is a line fault in A-phase line, B-phase line, and C-phase line, the line protection device on the power generation side takes any two-phase line for fault judgment, for example, takes AB-phase line for judgment.

[0082] In an embodiment of the present application, the first virtual potential may be a virtual potential corresponding to the fault line among multiple virtual potentials stored by the power generation side line protection device at the first moment. That is, the power generation side line protection device may determine the first virtual potential according to the target first voltage, the target first current and the first potential coefficient. The target first voltage is the voltage corresponding to the fault line among multiple first voltages, and the target first current is the current corresponding to the fault line among multiple first currents. The specific calculation process may refer to the above steps S204 to S205, and this application will not elaborate on it here.

[0083] Step S402: obtaining a fault voltage and a fault current corresponding to the fault line at a second moment, where the second moment is after the first moment and there is a preset time interval between the second moment and the first moment.

[0084] In an embodiment of the present application, the second moment may be the current moment, the first moment may be the moment 100 ms before the current moment, or may be the moment before the current moment and separated from the current moment by other preset time intervals. The present application does not limit the length of the preset time interval.

[0085] If the fault line is a single-phase line, the fault voltage U f It can be the same as the voltage corresponding to the fault line in the multiple second voltages obtained by the power generation side line protection device at the second moment, that is, U f =U φ , U φ Indicates the voltage corresponding to the fault line in the multiple second voltages. Fault current I f It can be the sum of the current corresponding to the fault line among the multiple second currents obtained by the power generation side line protection device at the second moment, and the product of the zero-sequence current and the zero-sequence compensation coefficient, that is, I f =I φ +kr×3I0. Among them, I φ represents the current corresponding to the fault line among the multiple second currents obtained by the power generation side line protection device at the second moment, kr represents the zero-sequence compensation coefficient, and 3I0 represents the zero-sequence current. The calculation formula of the zero-sequence current 3I0 can be: 3I0=I A +IB +I C , I A ,I B and I C They are respectively the current corresponding to the A-phase line, the current corresponding to the B-phase line and the current corresponding to the C-phase line among the multiple second currents.

[0086] If the fault line is a two-phase line, the fault voltage U f It can be the same as the voltage corresponding to the fault line in the multiple second voltages obtained by the power generation side line protection device at the second moment, that is, U f =U φφ , U φφ Indicates the voltage corresponding to the fault line in the plurality of second voltages. For example, if the fault line is the AB phase line, the voltage corresponding to the fault line is U AB . Fault current I f It can be the same as the current corresponding to the fault line in the multiple second currents obtained by the power generation side line protection device at the second moment, that is, I f =I φφ , where I φφ represents the current corresponding to the fault line in the multiple second currents. For example, if the fault line is the AB phase line, the current corresponding to the fault line is I AB .

[0087] If the fault line is a three-phase line, the line protection device on the generator side can execute the fault protection process through the AB phase line, BC phase line or CA phase line. f and fault current I f The method for determining is the same as when the fault line is a two-phase line, and this application will not elaborate on it here.

[0088] This application takes the fault line as a single-phase line as an example to illustrate the process of fault identification by the power generation side line protection device. It can be understood that when the fault line is a two-phase line or a three-phase line, the process of fault identification by the power generation side line protection device has the same or similar calculation principle as when the fault line is a single-phase line.

[0089] Step S403: determining a first voltage drop angle according to the first virtual potential, the fault voltage and the fault current, wherein the first voltage drop angle is used to characterize the angle difference between the voltage drop between the fault voltage and the first virtual potential and the voltage drop between the fault current and the set impedance.

[0090] When the new energy power generation system operates normally, the virtual potential is approximately equivalent to the potential of the power grid and will not change suddenly in a short period of time. When the new energy power generation system fails, the line protection device on the power generation side can use the characteristic that the virtual potential does not change in a short period of time to approximately equate the virtual potential at the first moment to the virtual potential at the second moment. Therefore, the line protection device on the power generation side can calculate the first voltage drop angle through the virtual potential at the first moment to realize the judgment of the line fault and improve the accuracy of fault judgment.

[0091] Exemplarily, the calculation formula of the first pressure drop angle ang2 may be:

[0092]

[0093] Among them, U f Indicates the fault voltage, V f (t-100) represents the virtual potential of the fault line at the first moment, t represents the second moment, I f Indicates the fault current. Z set It represents the protection action impedance setting value (setting impedance) of the distance protection setting, which is a fixed value.

[0094] Step S404: determining a first phase angle according to the fault voltage, the fault current and the setting impedance.

[0095] Exemplarily, the calculation formula of the first phase angle ang3 may be:

[0096]

[0097] Among them, U f Indicates the fault voltage, I f is the fault current, Z set represents the protection action impedance setting value (setting impedance) of the distance protection setting, and U1 represents the positive sequence voltage. For example, the calculation formula of the positive sequence voltage U1 of phase A can be: U1=(U A +a 2 U B +aU C ) / 3,U A , U B and U C They are the voltage corresponding to the A phase line, the voltage corresponding to the B phase line and the voltage corresponding to the C phase line in the three-phase voltage, a represents the positive sequence rotation factor, a=e (j2π / 3) .

[0098] Step S405: determining the fault category of the line protection device according to the first voltage drop angle, the first phase comparison angle and the preset angle range, the fault category including an in-zone fault and an out-of-zone fault.

[0099] The line protection device on the power generation side can determine the fault direction according to the first voltage drop angle. The fault direction includes a positive direction and a reverse direction. If the first voltage drop angle is within the first preset angle range, the fault direction is determined to be the reverse direction. If the first voltage drop angle is not within the first preset angle range, the fault direction is determined to be the positive direction.

[0100] Exemplarily, the first preset angle range may be [-10°, 10°), or other ranges, which are not limited in this application. When the first voltage drop angle is 0°, the power generation side line protection device can determine that the fault direction is in the reverse direction. This application sets an error margin of 0°±10°, which can improve the accuracy and fault tolerance of fault identification.

[0101] If the first voltage drop angle ang2 satisfies -10°(350°)≤ang2<10°, the fault direction is determined to be the reverse direction. If the first voltage drop angle ang2 satisfies 10°≤ang2<350°, the fault direction is determined to be the forward direction.

[0102] After determining the fault direction, the line protection device on the generating side can also determine the fault category according to the first phase comparison angle, and the fault category includes an in-zone fault and an out-of-zone fault.

[0103] If the fault direction is in the reverse direction and the first phase angle is within the second preset angle range, the power generation side line protection device determines that the fault type is an intra-zone fault. If the fault direction is in the positive direction and the first phase angle is within the third preset angle range, the power generation side line protection device determines that the fault type is an intra-zone fault. The second preset angle range is a sub-range of the third preset angle range, the maximum value of the third preset angle range is greater than the maximum value of the second preset angle range, and the minimum value of the third preset angle range is less than the minimum value of the second preset angle range.

[0104] Exemplarily, the second preset angle range may be (90°, 270°+δ), the third preset angle range may be (90°+δ, 270°), or other ranges, which are not limited in the present application. δ may be a fixed value, and the power generation side line protection device may determine the specific value of δ according to actual conditions.

[0105] If the fault direction is in the reverse direction, the first phase angle ang3 satisfies 90°+δ<ang3<270°, and the line protection device on the generating side determines that the fault type is an internal fault. If the fault direction is in the positive direction, the first phase angle ang3 satisfies 90°<ang3<270°+δ, and the line protection device on the generating side determines that the fault type is an internal fault.

[0106] If the fault type is an intra-zone fault, the line protection device on the power generation side may issue a first disconnection instruction to the circuit breaker corresponding to the faulty line, and the first disconnection instruction is used to instruct the circuit breaker to trip.

[0107] In the embodiment of the present application, when a reverse fault occurs on the power generation side, the fault current collected by the line protection device on the power generation side is the current provided by the power system, and the ideal value of the first voltage drop angle ang2 should be 0°, such as Figure 5 As shown in the figure, when an ungrounded fault occurs in the reverse direction of the protection device on the generator side, ang2 can be Figure 5 From the beginning of the fault to 20ms after the fault, the fluctuation of ang2 is large. After 20ms of calculation, the line protection device on the power generation side can determine the stable ang2 angle and determine that the fault direction is the opposite direction.

[0108] In the technical solution provided by the embodiment of the present application, the line protection device can obtain the first virtual potential corresponding to the fault line at the first moment, and the fault line is the line where the fault occurs in the multi-phase line. And obtain the fault voltage and fault current corresponding to the fault line at the second moment, the second moment is after the first moment, and the second moment and the first moment are separated by a preset time interval. And determine the first voltage drop angle according to the first virtual potential, the fault voltage and the fault current, and the first voltage drop angle is used to characterize the voltage drop between the fault voltage and the first virtual potential, and the angle difference between the voltage drop of the fault current and the set impedance. And determine the first phase angle according to the fault voltage, the fault current and the set impedance. Finally, the fault category of the line protection device is determined according to the first voltage drop angle, the first phase angle and the preset angle range. The fault category includes in-zone faults and out-of-zone faults, which can improve the accuracy of fault category identification and improve the stability of power system operation.

[0109] Embodiment 2.

[0110] In the embodiment of the present application, the current line protection device is taken as an example of a power receiving side line protection device, and the process of the power receiving side line protection device performing fault protection in the fault protection state is exemplarily described.

[0111] The process of the line protection device on the receiving side performing fault protection can be as follows: Figure 6 As shown, the following steps are included:

[0112] Step S601: obtaining a first virtual potential corresponding to a faulty line at a first moment, where the faulty line is a line in a multi-phase line where a fault occurs.

[0113] The method for the receiving-side line protection device to determine the faulty line from the multi-phase line has the same or similar calculation principle as the method for the generating-side line protection device to determine the faulty line from the multi-phase line in the above step S401, and is not described in detail in this application.

[0114] In an embodiment of the present application, the first virtual potential may be a virtual potential corresponding to the fault line among multiple virtual potentials stored by the receiving-side line protection device at the first moment. That is, the receiving-side line protection device may determine the first virtual potential according to the target first voltage, the target first current, and the first potential coefficient. The target first voltage is the voltage corresponding to the fault line among multiple first voltages, and the target first current is the current corresponding to the fault line among multiple first currents. The specific calculation process may refer to the above steps S204 to S205, and this application will not be repeated here.

[0115] Step S602: obtaining a fault voltage and a fault current corresponding to the fault line at a second moment, where the second moment is after the first moment and there is a preset time interval between the second moment and the first moment;

[0116] The method for determining the fault voltage and fault current by the power receiving side line protection device has the same or similar calculation principle as the method for determining the fault voltage and fault current by the power generating side line protection device in the above step S402, and is not elaborated in this application.

[0117] Step S603: determining a first voltage drop angle according to the first virtual potential, the fault voltage and the fault current, wherein the first voltage drop angle is used to characterize the angle difference between the voltage drop between the fault voltage and the first virtual potential and the voltage drop between the fault current and the set impedance.

[0118] The method for the receiving-side line protection device to determine the first voltage drop angle ang2 has the same or similar calculation principle as the method for the generating-side line protection device to determine the first voltage drop angle ang2 in the above step S403, and this application will not elaborate on it here.

[0119] Step S604: determining a first phase angle according to the fault voltage, the fault current and the setting impedance.

[0120] The method for determining the first phase angle ang3 by the power receiving side line protection device has the same or similar calculation principle as the method for determining the first phase angle ang3 by the power generating side line protection device in the above step S404, and this application will not elaborate on it here.

[0121] Step S605: determining the fault category of the line protection device according to the first voltage drop angle, the first phase comparison angle and the preset angle range, where the fault category includes an in-zone fault and an out-of-zone fault.

[0122] The line protection device on the power receiving side can determine the fault direction according to the first voltage drop angle, and the fault direction includes a positive direction and a reverse direction. If the first voltage drop angle is within the fourth preset angle range, the line protection device on the power receiving side determines that the fault direction is the positive direction. If the first voltage drop angle is not within the fourth preset angle range, the line protection device on the power receiving side determines that the fault direction is the reverse direction. There is no overlapping angle between the first preset angle range and the fourth preset angle range. The maximum value of the first preset angle range is 180° apart from the maximum value of the fourth preset angle range, and the minimum value of the first preset angle range is 180° apart from the minimum value of the fourth preset angle range.

[0123] Exemplarily, the fourth preset angle range may be [170°, 190°), or other ranges, which are not limited in this application. When the first voltage drop angle is 180°, the power receiving side line protection device can determine that the fault direction is the positive direction. This application sets an error margin of 0°±10°, which can improve the accuracy and fault tolerance of fault identification.

[0124] If the first voltage drop angle ang2 satisfies 170°≤ang2<190°, the line protection device on the receiving side determines that the fault direction is the positive direction. If the first voltage drop angle ang2 satisfies ang2≥190°, or the first voltage drop angle ang2 satisfies ang2<170°, the line protection device on the receiving side determines that the fault direction is the reverse direction.

[0125] After determining the fault direction, the line protection device at the power receiving side can also determine the fault category according to the first phase comparison angle. The fault category includes an in-zone fault and an out-of-zone fault.

[0126] If the fault direction is in the positive direction and the first phase angle is within the third preset angle range, the line protection device on the receiving side determines that the fault type is an internal fault. If the fault direction is in the reverse direction and the first phase angle is within the second preset angle range, the line protection device on the receiving side determines that the fault type is an internal fault.

[0127] Exemplarily, the second preset angle range may be (90°, 270°+δ), the third preset angle range may be (90°+δ, 270°), or other ranges, which are not limited in the present application. δ may be a fixed value, and the receiving side line protection device may determine the specific value of δ according to actual conditions.

[0128] If the fault direction is in the positive direction, the first phase angle ang3 satisfies 90°<ang3<270°+δ, and the line protection device on the receiving side determines that the fault type is an internal fault. If the fault direction is in the negative direction, the first phase angle ang3 satisfies 90°+δ<ang3<270°, and the line protection device on the receiving side determines that the fault type is an internal fault.

[0129] If the fault type is an intra-zone fault, the line protection device on the power receiving side may issue a first disconnection instruction to the circuit breaker corresponding to the faulty line, and the first disconnection instruction is used to instruct the circuit breaker to trip.

[0130] In the embodiment of the present application, when a positive fault occurs on the receiving side, the fault current collected by the line protection device on the receiving side is the current provided by the power system, and the ideal value of the first voltage drop angle ang2 should be 180°, such as Figure 7 As shown in the figure, when the line protection device on the receiving side has an ungrounded fault, ang2 can Figure 5 From the beginning of the fault to 20ms after the fault, the fluctuation of ang2 is large. After 20ms of calculation, the line protection device on the receiving side can determine the stable ang2 angle and determine that the fault direction is the positive direction.

[0131] It should be understood that, under the premise of no logical conflict, the above-mentioned various application embodiments can be implemented in combination with each other to meet actual application requirements. The specific embodiments or implementation plans obtained after these combinations still fall within the protection scope of this application.

[0132] Corresponding to the fault identification method in the above embodiment, the embodiment of the present application provides a distance protection device 80 for a new energy transmission line, which can be a line protection device, and the line protection device is respectively connected to a plurality of current transformers, and the plurality of current transformers are used to collect the current of a multi-phase line, and the plurality of current transformers correspond to the multi-phase line one by one. The distance protection device 80 for a new energy transmission line can be implemented by software, hardware, or a combination of both to become part or all of a computer device, and is used to execute the steps in the fault identification method in the above embodiment.

[0133] Figure 8 A schematic structural diagram of a distance protection device for a new energy transmission line provided in an embodiment of the present application is shown. For ease of explanation, only the parts related to the embodiment of the present application are shown.

[0134] Reference Figure 8 The distance protection device 80 of the new energy transmission line includes an acquisition module 810 and a determination module 820.

[0135] The acquisition module 810 is used to acquire a first virtual potential corresponding to a faulty line at a first moment, where the faulty line is a line in a multi-phase line where a fault occurs.

[0136] The acquisition module 810 is further used to acquire the fault voltage and fault current corresponding to the fault line at a second moment, where the second moment is after the first moment and there is a preset time interval between the second moment and the first moment.

[0137] The determination module 820 is used to determine a first voltage drop angle according to the first virtual potential, the fault voltage and the fault current, wherein the first voltage drop angle is used to characterize the voltage drop between the fault voltage and the first virtual potential, and the angle difference between the voltage drop between the fault current and the set impedance.

[0138] The determination module 820 is further configured to determine a first phase angle according to the fault voltage, the fault current and the setting impedance.

[0139] The determination module 820 is further configured to determine a fault category of the line protection device according to the first voltage drop angle, the first phase comparison angle and a preset angle range, wherein the fault category includes an in-zone fault and an out-of-zone fault.

[0140] In some embodiments, the acquisition module 810 is specifically used to: acquire multiple first voltages and multiple first currents corresponding to the multi-phase line at the first moment, and the multiple first voltages, multiple first currents and multi-phase lines correspond one to one. According to the multiple first voltages and multiple first currents, the active power of the line protection device is determined. If the active power is greater than 0, the first virtual potential is determined according to the target first voltage, the target first current and the first potential coefficient. The target first voltage is the voltage corresponding to the fault line among the multiple first voltages, and the target first current is the current corresponding to the target first voltage among the multiple first currents. The first virtual potential is positively correlated with the target first voltage, and the first virtual potential is negatively correlated with the target first current. If the active power is less than or equal to 0, the first virtual potential is determined according to the target first voltage, the target first current and the second potential coefficient. The first virtual potential is positively correlated with the target first voltage, the first virtual potential is positively correlated with the target first current, and the first potential coefficient is greater than the second potential coefficient.

[0141] In some embodiments, the determination module 820 is specifically used to: obtain multiple phase differences, multiple first voltages, multiple first currents and multiple phase differences correspond one to one, the first phase difference is the difference between the phase of any one of the multiple first voltages and the phase of a corresponding one of the multiple first currents, and the first phase difference is one of the multiple phase differences. Determine the active power according to the multiple first voltages, the multiple first currents and the multiple phase differences.

[0142] In some embodiments, the acquisition module 810 is specifically used to: acquire multiple second voltages and multiple second currents corresponding to the multi-phase line at the second moment, and the multiple second voltages, multiple second currents and the multi-phase line correspond one to one. Determine the fault line according to the multiple second voltages and the multiple second currents. Determine the fault voltage and the fault current according to the fault line, the fault voltage is the voltage corresponding to the fault line in the multiple second voltages, and the fault current is positively correlated with the current corresponding to the fault line in the multiple second currents.

[0143] In some embodiments, the multiple first voltages are multiple phase voltages corresponding to the multi-phase lines, the multiple first currents are multiple phase currents corresponding to the multi-phase lines, the multiple second voltages are multiple phase voltages corresponding to the multi-phase lines, and the multiple second currents are multiple phase currents corresponding to the multi-phase lines.

[0144] Or, the multiple first voltages are multiple line voltages corresponding to the multi-phase lines, the multiple first currents are multiple line currents corresponding to the multi-phase lines, the multiple second voltages are multiple line voltages corresponding to the multi-phase lines, and the multiple second currents are multiple line currents corresponding to the multi-phase lines.

[0145] In some embodiments, if the active power is greater than 0, the line protection device is a power generation side line protection device, the preset angle range includes a first preset angle range, a second preset angle range and a third preset angle range, and the determination module 820 is specifically used to: if the first voltage drop angle is within the first preset angle range, and the first phase angle is within the second preset angle range, then determine that the fault type is an intra-zone fault. If the first voltage drop angle is not within the first preset angle range, and the first phase angle is within the third preset angle range, then determine that the fault type is an intra-zone fault, the second preset angle range is a sub-range of the third preset angle range, the maximum value of the third preset angle range is greater than the maximum value of the second preset angle range, and the minimum value of the third preset angle range is less than the minimum value of the second preset angle range.

[0146] In some embodiments, if the active power is less than or equal to 0, the line protection device is a receiving-side line protection device, the preset angle range also includes a fourth preset angle range, and the determination module 820 is specifically used to: if the first voltage drop angle is within the fourth preset angle range, and the first phase angle is within the third preset angle range, then determine that the fault type is an intra-zone fault. If the first voltage drop angle is not within the fourth preset angle range, and the first phase angle is within the second preset angle range, then determine that the fault type is an intra-zone fault, the first preset angle range and the fourth preset angle range do not have an overlapping angle, the maximum value of the first preset angle range is 180° away from the maximum value of the fourth preset angle range, and the minimum value of the first preset angle range is 180° away from the minimum value of the fourth preset angle range.

[0147] In some embodiments, the determination module 820 is further used to: if the fault type is an intra-zone fault, issue a first disconnection instruction to the circuit breaker corresponding to the faulty line, wherein the first disconnection instruction is used to instruct the circuit breaker to trip.

[0148] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0149] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0150] Based on the same inventive concept, an embodiment of the present application also provides an electronic device.

[0151] Fig. 9 Schematic diagram of the structure of the electronic device provided in the embodiment of the present application. Fig. 9 As shown, the electronic device 90 of this embodiment includes: at least one processor 910 ( Fig. 9 Only one is shown in the figure), memory 920, and communication module 940, memory 920 stores computer program 930 that may be run on processor 910. When processor 910 executes computer program 930, steps in the above-mentioned fault identification method embodiment are implemented, such as Figure 4 Alternatively, when the processor 910 executes the computer program 930, the functions of each module / unit in the above-mentioned device embodiments are implemented, for example Figure 8 The functions of modules 810 to 820 are shown, and the communication module 940 can be a separate communication unit for communicating with an external server or terminal device.

[0152] The electronic device 90 may include, but is not limited to: a processor 910 and a memory 920. Those skilled in the art will appreciate that Fig. 9 It is only an example of the electronic device 90 and does not constitute a limitation of the electronic device 90. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the electronic device 90 may also include an input sending device, a network access device, a bus, etc.

[0153] The processor 910 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0154] In some embodiments, the memory 920 may be an internal storage unit of the electronic device 90, such as a hard disk or memory of the electronic device 90. The memory 920 may also be an external storage device of the electronic device 90, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the electronic device 90. The memory 920 may also include both an internal storage unit of the electronic device 90 and an external storage device. The memory 920 is used to store an operating system, an application program, a boot loader (BootLoader), data, and other programs, such as program codes of a computer program 930, etc. The memory 920 may also be used to temporarily store data that has been sent or is to be sent.

[0155] In addition, those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units.

[0156] An embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program runs on an electronic device, the electronic device executes the steps in the above-mentioned method embodiments.

[0157] An embodiment of the present application provides a chip, which includes a processor and a memory. The memory stores a computer program, and when the computer program is executed by the processor, the steps in the above-mentioned method embodiments are implemented.

[0158] An embodiment of the present application provides a computer program product. When the computer program product is run on an electronic device, the electronic device executes the steps in the above-mentioned method embodiments.

[0159] It should be understood that the processor mentioned in the embodiments of the present application may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0160] It should also be understood that the memory mentioned in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct memory bus random access memory (Direct Rambus RAM, DR RAM).

[0161] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0162] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0163] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0164] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the system embodiments described above are merely schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0165] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0166] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0167] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device capable of carrying the computer program code to a large-screen device, a recording medium, a computer memory, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), an electric carrier signal, a telecommunication signal, and a software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0168] Finally, it should be noted that the above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A distance protection method for a new energy transmission line, characterized in that: Applied to a line protection device, the line protection device is used to monitor the line status of a multi-phase line, the method comprises: Acquire a first virtual potential corresponding to a faulty line at a first moment, wherein the faulty line is a line in which a fault occurs in the multi-phase line; Acquire a fault voltage and a fault current corresponding to the fault line at a second moment, where the second moment is after the first moment, and the second moment is separated from the first moment by a preset time interval; Determine a first voltage drop angle according to the first virtual potential, the fault voltage and the fault current, wherein the first voltage drop angle is used to characterize the voltage drop between the fault voltage and the first virtual potential, and the angle difference between the voltage drop between the fault current and the set impedance; Determine a first phase angle according to the fault voltage, the fault current and the set impedance; The fault category of the line protection device is determined according to the first voltage drop angle, the first phase comparison angle and a preset angle range, and the fault category includes an in-zone fault and an out-of-zone fault.

2. The method according to claim 1, characterized in that The obtaining of a first virtual potential corresponding to the faulty line includes: Acquire a plurality of first voltages and a plurality of first currents corresponding to the multi-phase line at the first moment, wherein the plurality of first voltages, the plurality of first currents and the multi-phase line correspond one to one; determining an active power of the line protection device according to the plurality of first voltages and the plurality of first currents; If the active power is greater than 0, the first virtual potential is determined according to the target first voltage, the target first current and the first potential coefficient, the target first voltage is the voltage corresponding to the fault line among the multiple first voltages, the target first current is the current corresponding to the target first voltage among the multiple first currents, the first virtual potential is positively correlated with the target first voltage, and the first virtual potential is negatively correlated with the target first current; If the active power is less than or equal to 0, the first virtual potential is determined according to the target first voltage, the target first current and the second potential coefficient, the first virtual potential is positively correlated with the target first voltage, the first virtual potential is positively correlated with the target first current, and the first potential coefficient is greater than the second potential coefficient.

3. The method according to claim 2, characterized in that Determining the active power of the line protection device according to the plurality of first voltages and the plurality of first currents includes: Acquire a plurality of phase differences, wherein the plurality of first voltages, the plurality of first currents and the plurality of phase differences correspond one to one, a first phase difference being a difference between a phase of any one of the plurality of first voltages and a phase of a corresponding one of the plurality of first currents, and the first phase difference being one of the plurality of phase differences; The active power is determined based on the plurality of first voltages, the plurality of first currents, and the plurality of phase differences.

4. The method according to claim 3, characterized in that: The obtaining of the fault voltage and the fault current corresponding to the fault line at the second moment includes: Acquire a plurality of second voltages and a plurality of second currents corresponding to the multi-phase line at a second moment, wherein the plurality of second voltages, the plurality of second currents and the multi-phase line correspond one to one; Determining the fault line according to the plurality of second voltages and the plurality of second currents; The fault voltage and the fault current are determined according to the fault line, wherein the fault voltage is a voltage corresponding to the fault line among the multiple second voltages, and the fault current is positively correlated with a current corresponding to the fault line among the multiple second currents.

5. The method according to claim 4, characterized in that The multiple first voltages are multiple phase voltages corresponding to the multi-phase line, the multiple first currents are multiple phase currents corresponding to the multi-phase line, the multiple second voltages are multiple phase voltages corresponding to the multi-phase line, and the multiple second currents are multiple phase currents corresponding to the multi-phase line; Or, the multiple first voltages are multiple line voltages corresponding to the multi-phase line, the multiple first currents are multiple line currents corresponding to the multi-phase line, the multiple second voltages are multiple line voltages corresponding to the multi-phase line, and the multiple second currents are multiple line currents corresponding to the multi-phase line.

6. The method according to claim 5, characterized in that If the active power is greater than 0, the line protection device is a power generation side line protection device, the preset angle range includes a first preset angle range, a second preset angle range and a third preset angle range, and the fault type of the line protection device is determined according to the first voltage drop angle, the first phase angle and the preset angle range, including: If the first voltage drop angle is within the first preset angle range, and the first phase angle is within the second preset angle range, then the fault type is determined to be an intra-zone fault; If the first voltage drop angle is not within the first preset angle range, and the first phase comparison angle is within the third preset angle range, the fault type is determined to be an intra-zone fault, the second preset angle range is a subrange of the third preset angle range, the maximum value of the third preset angle range is greater than the maximum value of the second preset angle range, and the minimum value of the third preset angle range is less than the minimum value of the second preset angle range.

7. The method according to any one of claims 2 to 6, characterized in that: If the active power is less than or equal to 0, the line protection device is a receiving-side line protection device, the preset angle range further includes a fourth preset angle range, and determining the fault type of the line protection device according to the first voltage drop angle, the first phase angle and the preset angle range includes: If the first voltage drop angle is within the fourth preset angle range, and the first phase comparison angle is within the third preset angle range, then determining that the fault type is an intra-zone fault; If the first voltage drop angle is not within the fourth preset angle range, and the first phase ratio angle is within the second preset angle range, the fault type is determined to be an intra-zone fault, there is no overlapping angle between the first preset angle range and the fourth preset angle range, the maximum value of the first preset angle range is 180° apart from the maximum value of the fourth preset angle range, and the minimum value of the first preset angle range is 180° apart from the minimum value of the fourth preset angle range.

8. The method according to claim 1, characterized in that After determining the fault type of the line protection device according to the first voltage drop angle, the first phase comparison angle and the preset angle range, the method further includes: If the fault type is an intra-zone fault, a first disconnection instruction is issued to the circuit breaker corresponding to the faulty line, wherein the first disconnection instruction is used to instruct the circuit breaker to trip.

9. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the processor is configured to execute a computer program stored in the memory to implement the method as claimed in any one of claims 1 to 8.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method as described in any one of claims 1 to 8 is implemented.

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