Method and device for testing influence of new energy station fault response on dc control protection

Abstract

The present application relates to the field of new energy power generation system simulation detection technology, and discloses a new energy station fault response influence test method and device for direct current control protection, which establishes a real-time simulation model containing a new energy station and a direct current system, and equivalent power source models and grounding resistance models for simulating alternating current faults, configures operation parameters of the real-time simulation model according to the target new energy station output power to be tested, selects corresponding models from the equivalent power source models and the grounding resistance models as target fault simulation models according to the target alternating current fault type to be simulated, and establishes the connection between the models and the real-time simulation model; controls the target fault simulation model to simulate the corresponding target alternating current fault type, and then obtains response data of the real-time simulation model to perform corresponding test index evaluation, so as to determine whether the current test is passed. The present application realizes the test of the influence of the response of the new energy station to the direct current control protection when the alternating current fault occurs.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of simulation and detection of new energy power generation systems, and particularly relates to a method and device for testing the influence of fault response of a new energy station on DC control protection. BACKGROUND

[0002] When an AC fault occurs at the grid side of a new energy station such as a wind farm or a photovoltaic farm, it may have some impact on the grid side, such as grid voltage sag caused by the response of the new energy converter, and grid frequency change caused by the change in power output.

[0003] Therefore, it is necessary to carry out testing on the influence of the response of a new energy station when an AC fault occurs on the DC control protection, so as to control the performance of the new energy station connected to the grid. SUMMARY

[0004] The present application provides a method and device for testing the influence of fault response of a new energy station on DC control protection, which solves the technical problem of how to test the influence of the response of a new energy station when an AC fault occurs on the DC control protection.

[0005] The first aspect of the present application provides a method for testing the influence of fault response of a new energy station on DC control protection, comprising:

[0006] establishing a real-time simulation model containing a new energy station and a DC system, and an equivalent power source model and a grounding resistance model for simulating an AC fault; the equivalent power source model and the grounding resistance model are connected between the new energy station and the DC system in the real-time simulation model through a selection switch, and the new energy station and the DC system in the real-time simulation model are connected to a control protection device through a corresponding simulation interface respectively;

[0007] obtaining a target test scheme; the target test scheme includes a target new energy station output power to be tested and a target AC fault type to be simulated;

[0008] configuring the operating parameters of the real-time simulation model according to the target new energy station output power; the operating parameters include the environmental parameters at the new energy station in the real-time simulation model;

[0009] selecting a corresponding model from the equivalent power source model and the grounding resistance model as a target fault simulation model according to the target AC fault type, and establishing the connection between the target fault simulation model and the real-time simulation model;

[0010] controlling the target fault simulation model to simulate an AC fault corresponding to the target AC fault type;

[0011] acquire response data of the real-time simulation model to the ac fault simulated by the target fault simulation model;

[0012] evaluate a test index corresponding to the ac fault simulated by the target fault simulation model according to the response data, and determine whether the current test is passed based on the evaluation result of the test index.

[0013] According to an implementable manner of the first aspect of the present application, the establishing of the connection between the target fault simulation model and the real-time simulation model comprises:

[0014] The connection between the target fault simulation model and the real-time simulation model is established by controlling the opening and closing states of the selection switch.

[0015] According to an implementable manner of the first aspect of the present application, when the target fault simulation model is an equivalent power source model, the controlling of the target fault simulation model to simulate the ac fault corresponding to the target ac fault type comprises:

[0016] The voltage drop of the ac fault is simulated by changing the voltage setting value of the equivalent power source model.

[0017] When the target fault simulation model is a grounding resistance model, the controlling of the target fault simulation model to simulate the ac fault corresponding to the target ac fault type comprises:

[0018] The voltage drop of the ac fault is simulated by changing the resistance value of the grounding resistance model.

[0019] According to an implementable manner of the first aspect of the present application, the test index corresponding to the ac fault simulated by the equivalent power source model comprises the ac low-voltage ride-through index and the dc-ac low-voltage ride-through index of the new energy station, and the test index corresponding to the ac fault simulated by the grounding resistance model comprises the ac low-voltage ride-through index, the dc-ac low-voltage ride-through index and the grid stability standard index of the new energy station.

[0020] According to an implementable manner of the first aspect of the present application, the ac low-voltage ride-through index of the new energy station comprises:

[0021] When the voltage drops to 90% of the rated voltage, the new energy station should continue to run for at least 10 seconds, and the active power should be reduced to within 20% of the rated power within 3 seconds; when the voltage drops to 85% of the rated voltage, the new energy station should be able to automatically realize reactive power control; when the voltage drops to 80% of the rated voltage, the new energy station should continue to run for at least 3 seconds, and the active power should be reduced to within 5% of the rated power within 3 seconds; the new energy station should be able to realize reactive power regulation during low voltage ride through, and control the stability of the grid voltage.

[0022] According to an implementable manner of the first aspect of the application, the DC-AC low voltage ride through index comprises:

[0023] The transmission power of the DC system should be restored to 90% of the pre-fault value within 120ms from the moment of fault removal, and there should be no sustained oscillation of DC current and DC voltage during the restoration period.

[0024] According to an implementable manner of the first aspect of the application, the grid stability standard index comprises:

[0025] Satisfy transient stability: after the grid is disturbed, the relative swing between the units in the synchronous system is caused, and the system center point voltage gradually recovers after the first oscillation period and the second oscillation period are not out of step and synchronous damped oscillation is made;

[0026] Satisfy voltage stability: during the transient process after the power system receives a large disturbance, the load bus voltage should be restored to above 0.8p.u. within 10s, and the load bus voltage should be restored to above 0.9p.u. after the transient process ends;

[0027] Satisfy frequency stability: the system frequency can be quickly restored to between 49.2Hz and 50.5Hz after AC fault.

[0028] The second aspect of the application provides a new energy station fault response influence test method and device for DC control protection, characterized by comprising:

[0029] The establishment module is configured to establish a real-time simulation model containing a new energy station and a DC system, and an equivalent power source model and a grounding resistance model for simulating AC faults; the equivalent power source model and the grounding resistance model are connected between the new energy station and the DC system in the real-time simulation model through a selection switch, and the new energy station and the DC system in the real-time simulation model are connected to a control protection device through a corresponding simulation interface respectively;

[0030] The first acquisition module is configured to acquire a target test scheme; the target test scheme comprises a target new energy station output power required to be tested and a target AC fault type required to be simulated;

[0031] The configuration module is configured to configure operation parameters of the real-time simulation model according to the target new energy station output power; the operation parameters include environmental parameters at the new energy station in the real-time simulation model;

[0032] The selection connection module is configured to select a corresponding model as a target fault simulation model from the equivalent power source model and the grounding resistance model according to the target AC fault type, and establish a connection between the target fault simulation model and the real-time simulation model.

[0033] The control simulation module is configured to control the target fault simulation model to perform AC fault simulation corresponding to the target AC fault type.

[0034] The second acquisition module is configured to acquire response data of the real-time simulation model to the AC fault simulated by the target fault simulation model.

[0035] The evaluation judgment module is configured to evaluate a test index corresponding to the AC fault simulated by the target fault simulation model according to the response data, and judge whether the current test passes based on the obtained test index evaluation result.

[0036] According to an implementable manner of the second aspect of the present application, the selection connection module comprises:

[0037] The control unit is configured to establish the connection between the target fault simulation model and the real-time simulation model by controlling the opening and closing states of the selection switch.

[0038] According to an implementable manner of the second aspect of the present application, when the target fault simulation model is an equivalent power source model, the control simulation module comprises:

[0039] The first simulation unit is configured to simulate voltage drop of the AC fault by changing a voltage setting value of the equivalent power source model.

[0040] When the target fault simulation model is a grounding resistance model, the control simulation module comprises:

[0041] The second simulation unit is configured to simulate voltage drop of the AC fault by changing a resistance value of the grounding resistance model.

[0042] According to an implementable manner of the second aspect of the present application, the test index corresponding to the AC fault simulated by the equivalent power source model includes AC low voltage ride-through indexes and DC AC low voltage ride-through indexes of the new energy station, and the test index corresponding to the AC fault simulated by the grounding resistance model includes AC low voltage ride-through indexes, DC AC low voltage ride-through indexes and grid stability standard indexes of the new energy station.

[0043] According to an implementable manner of the second aspect of the present application, the AC low-voltage ride-through index of the new energy station comprises:

[0044] When the voltage drops to 90% of the rated voltage, the new energy station should continue to operate for at least 10 seconds, and should reduce its active power to within 20% of the rated power within 3 seconds; when the voltage drops to 85% of the rated voltage, the new energy station should be able to automatically implement reactive power control; when the voltage drops to 80% of the rated voltage, the new energy station should continue to operate for at least 3 seconds, and should reduce its active power to within 5% of the rated power within 3 seconds; the new energy station should be able to implement reactive power regulation and control the stability of its grid voltage during low-voltage ride-through.

[0045] According to an implementable manner of the second aspect of the present application, the DC / AC low-voltage ride-through index comprises:

[0046] The transmission power of the DC system should be restored to 90% of the pre-fault value within 120 ms from the moment of fault clearance, and there should be no sustained oscillation of DC current and DC voltage during the restoration period.

[0047] According to an implementable manner of the second aspect of the present application, the grid stability standard index comprises:

[0048] Satisfy transient stability: after the grid is disturbed, the relative swing of power angle between each unit in the synchronous system is caused, and after the first oscillation period and the second oscillation period, the synchronous damped oscillation is not out of step, and the hub voltage in the system gradually recovers;

[0049] Satisfy voltage stability: during the transient process after the power system receives a large disturbance, the load bus voltage should be restored to above 0.8 p.u. within 10s, and after the transient process ends, the load bus voltage should be restored to above 0.9 p.u.;

[0050] Satisfy frequency stability: after AC fault, the system frequency can quickly recover to between 49.2Hz and 50.5Hz.

[0051] The third aspect of the present application provides a new energy station fault response impact on DC control protection testing device, comprising:

[0052] The memory is used to store instructions; wherein the instructions are used to implement the new energy station fault response impact on DC control protection testing method according to any one of the implementable manners;

[0053] The processor is used to execute the instructions in the memory.

[0054] The computer readable storage medium of the fourth aspect of the present application stores a computer program, and the computer program is executed by a processor to realize the new energy station fault response influence test method on DC control protection that can be realized by any one of the above.

[0055] From the above technical solutions, the present application has the following advantages:

[0056] The present application establishes a real-time simulation model containing a new energy station and a DC system, and equivalent power source models and grounding resistance models for simulating AC faults, obtains a target test scheme including a target new energy station output power required for testing and a target AC fault type required for simulation, configures operation parameters of the real-time simulation model according to the target new energy station output power, selects corresponding models from the equivalent power source models and the grounding resistance models as a target fault simulation model according to the target AC fault type, establishes a connection between the target fault simulation model and the real-time simulation model, controls the target fault simulation model to simulate an AC fault of the corresponding target AC fault type, thereby obtaining response data of the real-time simulation model to the corresponding AC fault, and performs corresponding test index evaluation according to the response data to determine whether the current test is passed. The present application realizes the test of the influence of the response of the new energy station to the DC control protection when an AC fault occurs, which is conducive to realizing the control of the performance of the new energy station connected to the power grid and effectively maintaining the safe and stable operation of the power grid. BRIEF DESCRIPTION OF DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0058] Figure 1 A flowchart of a new energy station fault response influence test method is provided for an optional embodiment of the present application.

[0059] Figure 2 A circuit topology diagram of a real-time simulation model constructed when the new energy station is a photovoltaic station and the DC system is a three-terminal flexible DC system is provided for an optional embodiment of the present application.

[0060] Figure 3 A structure connection block diagram of a new energy station fault response influence test device is provided for an optional embodiment of the present application.

[0061] Reference signs:

[0062] 1 - establishing module; 2 - first obtaining module; 3 - configuring module; 4 - selecting connecting module; 5 - controlling simulating module; 6 - second obtaining module; 7 - evaluating judging module. DETAILED DESCRIPTION

[0063] The embodiment of the present application provides a new energy station fault response influence test method and device for DC control protection, and relates to the technical field of new energy station fault response influence test.

[0064] In order to make the technical scheme of the present application more apparent and easy to understand, the following will describe the technical scheme in the embodiments of the present application with reference to the accompanying drawings. Obviously, the embodiments described below are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0065] The present application provides a new energy station fault response influence test method for DC control protection.

[0066] Please refer to Figure 1 , Figure 1 The embodiment of the present application provides a new energy station fault response influence test method for DC control protection.

[0067] The embodiment of the present application provides a new energy station fault response influence test method for DC control protection.

[0068] Step S1, a real-time simulation model containing a new energy station and a DC system and an equivalent power source model and a grounding resistance model used to simulate an AC fault are established; the equivalent power source model and the grounding resistance model are connected between the new energy station and the DC system in the real-time simulation model through a selection switch, and the new energy station and the DC system in the real-time simulation model are connected to a control protection device through a corresponding simulation interface respectively.

[0069] In the embodiment, the type of the new energy station includes a photovoltaic station and a wind power station.

[0070] Taking the photovoltaic station as an example and taking the three-terminal flexible DC system as an example, the circuit topology of the real-time simulation model can be as shown in the figure. Figure 2 The three-terminal flexible DC system includes a converter station 1, a converter station 2 and a converter station 3.

[0071] Step S2, obtaining a target test scheme; the target test scheme includes a target new energy station output power of a required test and a target alternating current fault type of a required simulation.

[0072] Step S3, configuring an operation parameter of the real-time simulation model according to the target new energy station output power; the operation parameter includes an environmental parameter at a new energy station in the real-time simulation model.

[0073] As a specific implementation, the light intensity at the new energy station in the real-time simulation model is configured according to the target new energy station output power. By setting the environmental parameter such as the light intensity, the output power of the photovoltaic station in the real-time simulation model can be changed, and the output power of the direct current system changes with the change of the output power of the photovoltaic station.

[0074] In an implementable manner, a list in which a corresponding relationship between the target new energy station output power and the operation parameter of the real-time simulation model is stored is set in advance, so that the operation parameter corresponding to the target new energy station output power is matched through the list, and then the operation parameter of the real-time simulation model is configured according to the matched operation parameter value.

[0075] Step S4, selecting a corresponding model from the equivalent power source model and the grounding resistance model as a target fault simulation model according to the target alternating current fault type, and establishing a connection between the target fault simulation model and the real-time simulation model.

[0076] In an implementable manner, the establishing of the connection between the target fault simulation model and the real-time simulation model includes:

[0077] The connection between the target fault simulation model and the real-time simulation model is established by controlling the on-off state of the selection switch.

[0078] As an example, for the real-time simulation model shown in FIG. 1, the connection between the grounding resistance model and the real-time simulation model can be established by opening the selection switch, and the connection between the equivalent power source model and the real-time simulation model can be established by closing the selection switch. Figure 2

[0079] Step S5, controlling the target fault simulation model to perform alternating current fault simulation corresponding to the target alternating current fault type.

[0080] In an implementable manner, when the target fault simulation model is the equivalent power source model, the controlling of the target fault simulation model to perform alternating current fault simulation corresponding to the target alternating current fault type includes:

[0081] The voltage drop of the alternating current fault is simulated by changing the voltage setting value of the equivalent power source model. ​

[0082] When the target fault simulation model is a grounding resistance model, the control of the target fault simulation model to perform AC fault simulation corresponding to the target AC fault type comprises:

[0083] The voltage drop of the AC fault is simulated by changing the resistance value of the grounding resistance model.

[0084] In the embodiment of the application, there are two ways for response test of AC grounding fault: (1) AC fault is simulated by the grounding resistance model, and the grounding resistance is a variable resistance. The grounding resistance is determined according to the drop depth of AC voltage at the beginning of the fault. This way is used to test the influence of the new energy station on the DC after the AC fault; (2) the fault uses an infinite power source, and the voltage drop of the AC fault is simulated by changing the equivalent power voltage setting value, so as to test the response of the new energy station and the DC control to the voltage drop, and test whether the new energy and the DC can pass through under this voltage drop.

[0085] In step S6, response data of the AC fault simulated by the real-time simulation model for the target fault simulation model is obtained.

[0086] In step S7, a test index corresponding to the AC fault simulated by the target fault simulation model is evaluated according to the response data, and it is judged whether the current test passes based on the evaluation result of the obtained test index.

[0087] In an implementable way, the test index corresponding to the AC fault simulated by the equivalent power source model includes an AC low voltage ride-through index of the new energy station and a DC AC low voltage ride-through index, and the test index corresponding to the AC fault simulated by the grounding resistance model includes an AC low voltage ride-through index of the new energy station, a DC AC low voltage ride-through index, and a power grid stability standard index.

[0088] In an implementable way, the AC low voltage ride-through index of the new energy station includes:

[0089] When the voltage drops to 90% of the rated voltage, the wind farm and the photovoltaic should continue to run for at least 10 seconds, and when the voltage drops to 80% of the rated voltage, the wind farm and the photovoltaic should continue to run for at least 3 seconds; in addition, when the voltage drops to 85% of the rated voltage, the wind farm and the photovoltaic should be able to automatically realize reactive power control to ensure their stable operation under low voltage;

[0090] When the voltage drops to 90% of the rated voltage, the wind farm and photovoltaic should reduce its active power to within 20% of the rated power within 3 seconds; when the voltage drops to 80% of the rated voltage, the wind farm and photovoltaic should reduce its active power to within 5% of the rated power within 3 seconds; at the same time, the wind farm and photovoltaic should be able to realize reactive power regulation during low voltage ride through, and control the stability of its grid voltage.

[0091] In an implementable manner, the DC-AC low voltage ride through index comprises:

[0092] The transmission power of the DC system should be restored to 90% of the pre-fault within 120ms from the moment of fault removal, and there is no sustained oscillation of DC current and DC voltage during the recovery period.

[0093] In an implementable manner, the grid stability standard index comprises:

[0094] Satisfy transient stability: after the grid is disturbed, the relative swing of power angle between each unit in the synchronous system is caused, and the system center point voltage gradually recovers after the first oscillation period and the second oscillation period are not out of step and synchronous damped oscillation is made;

[0095] Satisfy voltage stability: during the transient process after the power system receives a large disturbance, the load bus voltage should be restored to above 0.8p.u. within 10s, and the load bus voltage should be restored to above 0.9p.u. after the transient process ends;

[0096] Satisfy frequency stability: the system frequency can be quickly restored to between 49.2Hz and 50.5Hz after AC fault.

[0097] The above-mentioned embodiments of the present application realize the test on the influence of the response of the new energy station to the AC fault on the DC control protection, which is beneficial to realize the control of the performance of the new energy station connected to the grid and effectively maintain the safe and stable operation of the grid.

[0098] The present application also provides a new energy station fault response DC control protection impact test device, which can be used to execute the new energy station fault response DC control protection impact test method of any one of the above-mentioned embodiments of the present application.

[0099] Please refer to Figure 3 , Figure 3 The structure connection block diagram of the new energy station fault response DC control protection impact test device provided by the embodiment of the present application is shown.

[0100] The new energy station fault response DC control protection impact test device provided by the embodiment of the present application comprises:

[0101] The establishing module 1 is configured to establish a real-time simulation model of a new energy station and a DC system, and an equivalent power source model and a grounding resistance model used to simulate an AC fault; the equivalent power source model and the grounding resistance model are connected between the new energy station and the DC system in the real-time simulation model through a selection switch, and the new energy station and the DC system in the real-time simulation model are connected to a control and protection device through a corresponding simulation interface;

[0102] The first obtaining module 2 is configured to obtain a target test scheme; the target test scheme includes a target new energy station output power required to be tested and a target AC fault type required to be simulated;

[0103] The configuring module 3 is configured to configure an operation parameter of the real-time simulation model according to the target new energy station output power; the operation parameter includes an environmental parameter at the new energy station in the real-time simulation model;

[0104] The selection and connection module 4 is configured to select a corresponding model as a target fault simulation model from the equivalent power source model and the grounding resistance model according to the target AC fault type, and establish a connection between the target fault simulation model and the real-time simulation model;

[0105] The control simulation module 5 is configured to control the target fault simulation model to perform AC fault simulation corresponding to the target AC fault type;

[0106] The second obtaining module 6 is configured to obtain response data of the real-time simulation model to the AC fault simulated by the target fault simulation model;

[0107] The evaluation and judgment module 7 is configured to evaluate a test index corresponding to the AC fault simulated by the target fault simulation model according to the response data, and judge whether the current test passes based on an evaluation result of the test index.

[0108] In an implementable manner, the selection and connection module 4 includes:

[0109] The control unit is configured to establish the connection between the target fault simulation model and the real-time simulation model by controlling the on-off state of the selection switch.

[0110] In an implementable manner, when the target fault simulation model is an equivalent power source model, the control simulation module 5 includes:

[0111] The first simulation unit is configured to simulate voltage drop of the AC fault by changing a voltage setting value of the equivalent power source model;

[0112] When the target fault simulation model is a grounding resistance model, the control simulation module 5 includes:

[0113] a second simulation unit, configured to simulate voltage sag of the AC fault by changing the resistance value of the grounding resistance model.

[0114] In an implementable manner, the test index corresponding to the AC fault simulated by the equivalent power source model includes an AC low voltage ride through index and a DC-AC low voltage ride through index of the new energy station, and the test index corresponding to the AC fault simulated by the grounding resistance model includes the AC low voltage ride through index, the DC-AC low voltage ride through index and a grid stability standard index of the new energy station.

[0115] In an implementable manner, the AC low voltage ride through index of the new energy station includes:

[0116] When the voltage drops to 90% of the rated voltage, the new energy station should continue to operate for at least 10 seconds, and should reduce its active power to within 20% of the rated power within 3 seconds; when the voltage drops to 85% of the rated voltage, the new energy station should be able to automatically implement reactive power control; when the voltage drops to 80% of the rated voltage, the new energy station should continue to operate for at least 3 seconds, and should reduce its active power to within 5% of the rated power within 3 seconds; the new energy station should be able to implement reactive power regulation during low voltage ride through, and control the stability of its grid voltage.

[0117] In an implementable manner, the DC-AC low voltage ride through index includes:

[0118] The transmission power of the DC system should be restored to 90% of that before the fault within 120 ms from the moment of fault clearance, and there should be no sustained oscillation of DC current and DC voltage during the recovery period.

[0119] In an implementable manner, the grid stability standard index includes:

[0120] Satisfy transient stability: after the grid is disturbed, the relative swing between each unit in the synchronous system is caused, and the system does not lose step after the first oscillation period and the second oscillation period, and synchronous damped oscillation is made, and the hub voltage in the system gradually recovers;

[0121] Satisfy voltage stability: during the transient process after the power system receives a large disturbance, the load bus voltage should be restored to above 0.8 p.u. within 10 s, and the load bus voltage should be restored to above 0.9 p.u. after the transient process ends;

[0122] Satisfy frequency stability: the system frequency can be quickly restored to between 49.2 Hz and 50.5 Hz after the AC fault.

[0123] The application further provides a new energy station fault response and DC control protection influence test device, comprising:

[0124] a memory for storing instructions; wherein the instructions are used to implement the new energy station fault response influence on DC control protection test method according to any one of the preceding embodiments.

[0125] a processor for executing the instructions in the memory.

[0126] The application further provides a computer readable storage medium, and the computer readable storage medium stores a computer program.

[0127] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices, modules and units can refer to the corresponding processes in the foregoing method embodiments, and the specific beneficial effects of the above-described devices, modules and units can refer to the corresponding beneficial effects in the foregoing method embodiments, which will not be repeated here.

[0128] In several 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 device embodiments described above are merely schematic, for example, the division of the modules is only a logical function division, and actual implementation can have another division manner, for example, a plurality of modules or components can be combined or integrated into another device, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed modules can be indirect coupling or communication connection through some interfaces, devices or modules, which can be electrical, mechanical or other forms.

[0129] The modules described as separate components can or can not be physically separated, and the components displayed as modules can or can not be physical modules, that is, they can be located in one place, or can be distributed on a plurality of network modules. According to actual needs, some or all of the modules can be selected to achieve the purpose of the embodiment scheme.

[0130] In addition, the functional modules in each embodiment of the present application can be integrated in one processing module, or each module can exist physically, or two or more modules can be integrated in one module. The integrated module can be realized in the form of hardware or in the form of a software functional module.

[0131] The integrated module, if implemented in the form of a software function module and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art, or all or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0132] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some technical features; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for testing the impact of fault response at new energy power plants on DC control and protection, characterized in that, include: Establish a real-time simulation model that includes new energy power stations and DC systems, as well as an equivalent power source model and a grounding resistance model to simulate AC faults; The equivalent power source model and the grounding resistance model are connected between the new energy power station and the DC system in the real-time simulation model through a selection switch. The new energy power station and the DC system in the real-time simulation model are respectively connected to the control and protection devices through corresponding simulation interfaces. Obtain the target test plan; The target test plan includes the target output power of the target new energy power station to be tested and the target AC fault types to be simulated. The operating parameters of the real-time simulation model are configured according to the output power of the target renewable energy power station; the operating parameters include the environmental parameters at the renewable energy power station in the real-time simulation model; Based on the target AC fault type, a corresponding model is selected from the equivalent power supply model and the grounding resistance model as the target fault simulation model, and a connection is established between the target fault simulation model and the real-time simulation model. The target fault simulation model is controlled to simulate an AC fault corresponding to the target AC fault type. Obtain the response data of the real-time simulation model to the AC fault simulated by the target fault simulation model; The test indicators corresponding to the AC fault simulated by the target fault simulation model are evaluated based on the response data, and the current test is judged as passed based on the evaluation results of the obtained test indicators. The test indicators corresponding to AC faults simulated by the equivalent power source model include AC low voltage ride-through indicators and DC AC low voltage ride-through indicators for new energy power plants. The test indicators corresponding to AC faults simulated by the grounding resistance model include AC low voltage ride-through indicators, DC AC low voltage ride-through indicators, and grid stability standard indicators for new energy power plants.

2. The test method for the impact of fault response of new energy power stations on DC control and protection according to claim 1, characterized in that, The process of establishing the connection between the target fault simulation model and the real-time simulation model includes: The connection between the target fault simulation model and the real-time simulation model is established by controlling the opening and closing state of the selection switch.

3. The test method for the impact of fault response of new energy power stations on DC control and protection according to claim 1, characterized in that, When the target fault simulation model is an equivalent power source model, controlling the target fault simulation model to perform AC fault simulation corresponding to the target AC fault type includes: The voltage drop during an AC fault is simulated by changing the voltage setpoint of the equivalent power source model. When the target fault simulation model is a grounding resistance model, controlling the target fault simulation model to perform AC fault simulation corresponding to the target AC fault type includes: Voltage drops during AC faults are simulated by changing the resistance value of a grounding resistance model.

4. The test method for the impact of fault response of new energy power stations on DC control and protection according to claim 1, characterized in that, The AC low-voltage ride-through parameters for the aforementioned new energy power stations include: When the voltage drops to 90% of the rated voltage, the renewable energy power station should continue to operate for at least 10 seconds and reduce its active power to within 20% of the rated power within 3 seconds; when the voltage drops to 85% of the rated voltage, the renewable energy power station should be able to automatically achieve reactive power control; when the voltage drops to 80% of the rated voltage, the renewable energy power station should continue to operate for at least 3 seconds and reduce its active power to within 5% of the rated power within 3 seconds; the renewable energy power station should be able to achieve reactive power regulation during low voltage ride-through and control the stability of its grid voltage.

5. The test method for the impact of fault response of new energy power stations on DC control and protection according to claim 1, characterized in that, The DC / AC low-voltage ride-through parameters include: The power output of the DC system should recover to 90% of the pre-fault level within 120ms from the moment the fault is cleared, and there should be no continuous oscillation of DC current and DC voltage during the recovery period.

6. The test method for the impact of fault response of new energy power stations on DC control and protection according to claim 1, characterized in that, The power grid stability standard indicators include: Satisfying transient stability: After the power grid is disturbed, the power angle of each unit in the synchronous system fluctuates relatively. After the first oscillation period and the second oscillation period, the system does not lose synchronization and performs synchronous decaying oscillation, and the voltage of the central point of the system gradually recovers. Voltage stability must be met: During the transient process following a large disturbance to the power system, the load bus voltage should recover to above 0.8 pu within 10 seconds, and after the transient process ends, the load bus voltage should recover to above 0.9 pu. Frequency stability is guaranteed: the system frequency can quickly recover to between 49.2Hz and 50.5Hz after an AC fault.

7. A testing device for the impact of fault response at new energy power plants on DC control and protection, characterized in that, include: A module is established to create a real-time simulation model of a new energy power station and a DC system, as well as an equivalent power source model and a grounding resistance model to simulate AC faults. The equivalent power source model and the grounding resistance model are connected between the new energy power station and the DC system in the real-time simulation model through a selection switch. The new energy power station and the DC system in the real-time simulation model are respectively connected to the control and protection devices through corresponding simulation interfaces. The first acquisition module is used to acquire the target test plan; The target test plan includes the target output power of the target new energy power station to be tested and the target AC fault types to be simulated. The configuration module is used to configure the operating parameters of the real-time simulation model according to the output power of the target renewable energy power station; the operating parameters include the environmental parameters at the renewable energy power station in the real-time simulation model; The selection module is used to select a corresponding model from the equivalent power supply model and the grounding resistance model as the target fault simulation model according to the target AC fault type, and to establish a connection between the target fault simulation model and the real-time simulation model. The control simulation module is used to control the target fault simulation model to simulate AC faults corresponding to the target AC fault type. The second acquisition module is used to acquire the response data of the real-time simulation model to the AC fault simulated by the target fault simulation model; The evaluation and judgment module is used to evaluate the test indicators corresponding to the AC fault simulated by the target fault simulation model based on the response data, and to determine whether the current test passes based on the evaluation results of the obtained test indicators. The test indicators corresponding to AC faults simulated by the equivalent power source model include AC low voltage ride-through indicators and DC AC low voltage ride-through indicators for new energy power plants. The test indicators corresponding to AC faults simulated by the grounding resistance model include AC low voltage ride-through indicators, DC AC low voltage ride-through indicators, and grid stability standard indicators for new energy power plants.

8. A testing device for the impact of fault response at new energy power plants on DC control and protection, characterized in that, include: A memory for storing instructions; wherein the instructions are used to implement the test method for the impact of fault response of new energy power stations on DC control and protection as described in any one of claims 1-6; A processor for executing instructions in the memory.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the test method for the impact of fault response of new energy power stations on DC control and protection as described in any one of claims 1-6.

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