CN116029152B - Protection adaptability determination method and device for new energy station - Google Patents
Protection adaptability determination method and device for new energy station Download PDFInfo
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Abstract
The method and the device for determining the protection adaptability of the new energy station comprise the following steps: under different preset operation modes, performing fault current change processing by using a new energy station model to obtain an end-to-end monopole layer flexible-to-straight system model; performing fault simulation processing on preset fault points by using an end-to-end monopole layer flexible-to-straight system model to obtain fault simulation data corresponding to each fault point; performing system starting judgment according to the fault simulation data, and performing wave recording processing according to a preset time point if the system is started successfully to obtain a short-circuit current matrix; and carrying out full-cycle Fourier transform on the short-circuit current matrix to obtain a short-circuit current fundamental wave effective value, and determining protection sensitivity and action coefficients corresponding to each fault point to obtain a protection adaptability result. The invention combines fault simulation and protection adaptability check, realizes effective simulation and analysis of the fault of the new energy station which is connected with the flexible direct control, and provides a feasible basis for flexible direct control protection and policy optimization research.
Description
Technical Field
The invention relates to the technical field of new energy stations, in particular to a method and a device for determining protection adaptability of a new energy station.
Background
The use of high proportion power electronic equipment in a flexible direct current transmission system causes that partial frequency bands are in negative damping characteristics due to inherent characteristics such as link delay and the like, meanwhile, the current source characteristics of new energy are not capable of providing the same moment of inertia and system damping as those of a synchronous generator, the factors make transient characteristics after the fault of a new energy station connected with flexible and straight more complex, and the practical and effective research results are difficult to obtain by the traditional fault simulation and protection adaptability analysis method.
Meanwhile, digital simulation under the traditional electromechanical transient precision only considers the change of amplitude and phase angle of fundamental frequency on the performance demonstration of differential protection action, distance protection action, direction element action and the like, and cannot reflect millisecond transient changes such as higher harmonic wave, high-low pass, overvoltage and the like.
Disclosure of Invention
Aiming at the problems existing in the prior art, the main purpose of the embodiment of the invention is to provide a method and a device for determining the protection adaptability of a new energy station, which realize effective simulation and analysis of faults of the new energy station which are connected with flexible and straight, and provide a feasible basis for flexible and straight control protection and policy optimization research.
In order to achieve the above object, an embodiment of the present invention provides a protection adaptability determining method for a new energy station, where the method includes:
Under different preset operation modes, performing fault current change processing by utilizing a new energy station model constructed in advance to obtain an end-to-end monopole layer flexible-to-straight system model;
Performing fault simulation processing on preset fault points by using an end-to-end monopole layer flexible-to-straight system model to obtain fault simulation data corresponding to each fault point;
Performing system starting judgment according to the fault simulation data, and performing wave recording processing according to a preset time point to obtain a short-circuit current matrix if the obtained system starting judgment result is that the starting is successful;
Performing full-cycle Fourier transform on the short-circuit current matrix to obtain a short-circuit current fundamental wave effective value;
And determining the protection sensitivity and the action coefficient corresponding to each fault point according to the effective value of the short-circuit current fundamental wave, and obtaining a protection adaptability result by utilizing the protection sensitivity and the action coefficient corresponding to each fault point.
Optionally, in an embodiment of the present invention, under different preset operation modes, performing fault current change processing by using a new energy station model built in advance, and obtaining an end-to-end monopole layer flexible-direct system model includes:
under different preset operation modes, single-phase grounding fault simulation is carried out on the same fault type of the same converter station by utilizing a new energy station model constructed in advance, so as to obtain fault current change data;
And determining an end-to-end monopole layer flexible-direct system model corresponding to the minimum short-circuit current by utilizing the fault current change data.
Optionally, in an embodiment of the present invention, performing the system start-up determination according to the fault simulation data includes:
Judging whether the active output data and the reactive output data reach preset rated values or not according to the active output data and the reactive output data in the fault simulation data;
and if the active output data and the reactive output data reach the preset rated values, determining that the system start judgment result is successful start.
Optionally, in an embodiment of the present invention, determining protection sensitivity and action coefficient corresponding to each fault point according to the effective value of the short-circuit current fundamental wave includes:
determining the sensitivity corresponding to the protection action time window by utilizing a preset protection action time window;
if the sensitivity corresponding to the protection action time window is smaller than a preset sensitivity threshold value, determining the protection sensitivity corresponding to each fault point according to the short-circuit current fundamental wave effective value;
according to load data in the end-to-end monopole layer flexible-direct system model, determining a station load working condition corresponding to the load data;
And if the action coefficient corresponding to the station load working condition is smaller than a preset action coefficient threshold value, determining the action coefficient corresponding to each fault point according to the effective value of the short-circuit current fundamental wave.
The embodiment of the invention also provides a device for determining the protection adaptability of the new energy station, which comprises the following steps:
The system model module is used for carrying out fault current change processing by utilizing a pre-constructed new energy station model under different preset operation modes to obtain an end-to-end monopole layer flexible-to-straight system model;
The fault simulation module is used for performing fault simulation processing on preset fault points by using an end-to-end monopole layer flexible-to-straight system model to obtain fault simulation data corresponding to each fault point;
the current matrix module is used for carrying out system starting judgment according to the fault simulation data, and if the obtained system starting judgment result is that the starting is successful, carrying out wave recording processing according to a preset time point to obtain a short-circuit current matrix;
the short-circuit current module is used for carrying out full-cycle Fourier transform on the short-circuit current matrix to obtain a short-circuit current fundamental wave effective value;
and the adaptive result module is used for determining the protection sensitivity and the action coefficient corresponding to each fault point according to the short-circuit current fundamental wave effective value, and obtaining a protection adaptive result by utilizing the protection sensitivity and the action coefficient corresponding to each fault point.
Optionally, in an embodiment of the present invention, the system model module includes:
The fault current unit is used for carrying out single-phase earth fault simulation on the same fault type of the same converter station by utilizing a new energy station model constructed in advance under different preset operation modes to obtain fault current change data;
And the system model unit is used for determining an end-to-end monopole layer flexible-to-straight system model corresponding to the minimum short circuit current by utilizing the fault current change data.
Optionally, in an embodiment of the present invention, the current matrix module includes:
the output data unit is used for judging whether the active output data and the reactive output data reach a preset rated value according to the active output data and the reactive output data in the fault simulation data;
and the starting judging unit is used for determining that the system starting judging result is successful in starting if the active output data and the reactive output data reach the preset rated values.
Optionally, in an embodiment of the present invention, the adaptive result module includes:
the time window unit is used for determining the sensitivity corresponding to the protection action time window by utilizing a preset protection action time window;
The sensitivity unit is used for determining the protection sensitivity corresponding to each fault point according to the effective value of the short-circuit current fundamental wave if the sensitivity corresponding to the protection action time window is smaller than the preset sensitivity threshold value;
The load data unit is used for determining the station load working condition corresponding to the load data according to the load data in the end-to-end monopole layer flexible-direct system model;
and the action coefficient unit is used for determining the action coefficient corresponding to each fault point according to the effective value of the short-circuit current fundamental wave if the action coefficient corresponding to the station load working condition is smaller than the preset action coefficient threshold value.
The invention also provides an electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the above method when executing the program.
The present invention also provides a computer readable storage medium storing a computer program for executing the above method.
The invention also provides a computer program product comprising computer programs/instructions which when executed by a processor implement the steps of the above method.
According to the invention, by carrying out fault simulation processing on the new energy station model, fault simulation and protection adaptability checking are considered, and effective simulation and analysis on the fault of the new energy station which is connected with the flexible direct control station are realized, so that a feasible basis is provided for flexible direct control protection and policy optimization research.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a flow chart of a prior art simulation software-based protection adaptability analysis;
FIG. 2 is a flowchart of a method for determining protection adaptability of a new energy station according to an embodiment of the present invention;
FIG. 3 is a flow chart of obtaining an end-to-end monopole layer flexible-to-straight system model in an embodiment of the invention;
FIG. 4 is a flowchart of a system start-up determination in an embodiment of the present invention;
FIG. 5 is a flowchart of determining a protection sensitivity and an action coefficient according to an embodiment of the present invention;
FIG. 6 is a schematic diagram of a basic architecture of a new energy station with soft and straight access in an embodiment of the present invention;
FIG. 7 is a flow chart of a protection adaptability analysis in an embodiment of the invention;
Fig. 8 is a schematic structural diagram of a protection adaptability determining device for a new energy station according to an embodiment of the present invention;
FIG. 9 is a schematic diagram of a system model module according to an embodiment of the present invention;
fig. 10 is a schematic structural diagram of a recording data module according to an embodiment of the present invention;
FIG. 11 is a schematic structural diagram of an adaptive result module according to an embodiment of the present invention;
Fig. 12 is a schematic structural diagram of an electronic device according to an embodiment of the invention.
Detailed Description
The embodiment of the invention provides a method and a device for determining protection adaptability of a new energy station.
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
As shown in fig. 1, which is a flow chart of the existing protection adaptability analysis based on simulation software, the current flexible direct current transmission system and access station real-time simulation technical method is as shown in fig. 1, and the design of a system protection scheme and the result check are completed by constructing a station and a line model comprising a fan and a photovoltaic in an all-digital real-time simulation device ADPSS of a power system according to simulation results, protection principles and calculated fixed values.
The simulation calculation steps shown in fig. 1 are as follows:
(1) And (3) establishing a flexible straight net rack model, and adjusting parameters of the net rack model according to the computing capacity of computing resources and the actual characteristics of the system.
(2) And (3) perfecting a line model connected with the flexible straight net rack, setting fault points, and performing fault simulation to obtain system fault simulation data.
(3) According to the protection principle, a phase selection and protection configuration scheme is determined, protection modes such as distance protection, differential protection and the like are checked according to the simulation result, whether accurate actions can be performed is judged, and the four-dimensional protection requirement is met.
In the prior art, for the real-time power system stability discrimination simulation, the following two defects exist:
1. Under the electromechanical transient precision, the existing equivalent impedance model with new energy access is influenced by a control strategy and fault simulation, the amplitude and the phase of the equivalent impedance model are changed, so that the simulation result is inaccurate, and the factors such as higher harmonic waves are lacked, so that the application with higher precision is not supported. Meanwhile, the system is limited by resource calculation force, cannot realize real-time simulation, lacks real-time observation capability on system change, and has an unobvious high-frequency oscillation effect on a flexible and straight system.
2. The existing relay protection related research, including sensitivity calculation and action coefficient calculation methods, are still based on the traditional alternating current system, do not consider the low inertia weak damping characteristic and fault ride through capability of the flexible direct current power grid, and are not fully applicable to analysis of new energy stations under flexible direct entry.
Therefore, an effective protection adaptability analysis method is needed, and effective simulation and analysis of faults of the new energy station which is connected with the flexible and straight are realized by considering fault simulation and protection adaptability check under electromagnetic transient precision of the system, so that a feasible basis is provided for flexible and straight control protection and strategy optimization research.
Fig. 2 is a flowchart of a method for determining protection adaptability of a new energy station according to an embodiment of the present invention, where an execution body of the method for determining protection adaptability of a new energy station according to an embodiment of the present invention includes, but is not limited to, a computer. According to the invention, by carrying out fault simulation processing on the new energy station model, fault simulation and protection adaptability check under the electromagnetic transient precision of the system are considered, and effective simulation and analysis on the fault of the new energy station which is connected with the flexible direct control are realized, so that a feasible basis is provided for flexible direct control protection and policy optimization research. The method shown in the figure comprises the following steps:
Step S1, under different preset operation modes, performing fault current change processing by utilizing a new energy station model built in advance to obtain an end-to-end monopole layer flexible-to-straight system model;
s2, performing fault simulation processing on preset fault points by using an end-to-end monopole layer flexible-to-straight system model to obtain fault simulation data corresponding to each fault point;
Step S3, performing system start judgment according to the fault simulation data, and performing wave recording processing according to a preset time point to obtain a short-circuit current matrix if the obtained system start judgment result is that the start is successful;
s4, performing full-cycle Fourier transform on the short-circuit current matrix to obtain a short-circuit current fundamental wave effective value;
And S5, determining protection sensitivity and action coefficient corresponding to each fault point according to the effective value of the short-circuit current fundamental wave, and obtaining a protection adaptability result by utilizing the protection sensitivity and action coefficient corresponding to each fault point.
The four-terminal flexible direct-current ring network and the accessed new energy station model are built in advance, and specifically, model parameters and control modes are determined by means of actual converter parameters. The model is built in a conventional manner, and will not be described in detail herein.
As an embodiment of the present invention, as shown in fig. 3, under different preset operation modes, performing fault current change processing by using a pre-constructed new energy station model, and obtaining an end-to-end monopole layer flexible-direct system model includes:
Step S21, under different preset operation modes, single-phase grounding fault simulation is carried out on the same fault type of the same converter station by utilizing a new energy station model constructed in advance, so as to obtain fault current change data;
and S22, determining an end-to-end monopole layer flexible-direct system model corresponding to the minimum short-circuit current by using the fault current change data.
The fault current change conditions of the same fault type of the same transmitting-end converter station under different operation modes are compared, particularly, the simulation single-phase earth fault under the multiple operation modes of single-pole and double-pole four-end ring networks, end-to-end and three-end and the like is respectively compared with the current effective value of the fault phase, the operation mode with the minimum short-circuit current is selected for subsequent field station protection adaptability analysis, and the end-to-end single-pole layer flexible-to-direct system model and the short-circuit current matrix are obtained.
Further, based on an end-to-end monopole layer flexible-direct system model, whether the voltage of a new energy station access flexible straight line bus and the voltage level of a main transformer high-low voltage side in the field meet preset engineering requirements or not under a steady state condition is confirmed, after no errors, new energy side, middle point, station side measuring points and outside-line-side measuring points in a line area are selected as fault points, a station main transformer high-voltage side, a station main transformer low-voltage side and a station main transformer low-voltage bus are selected as field fault points, fault simulation processing is carried out, and fault simulation data corresponding to each fault point are obtained.
Specifically, after fault simulation processing is performed through preset fault points in the model, the obtained fault simulation data comprise line and main transformer voltage and current data under all faults, and photovoltaic active power output level of the fan, direct current voltage of a transmitting and receiving end and the like.
As an embodiment of the present invention, as shown in fig. 4, performing system start-up judgment according to fault simulation data includes:
step S31, judging whether the active output data and the reactive output data reach preset rated values or not according to the active output data and the reactive output data in the fault simulation data;
Step S32, if the active output data and the reactive output data reach the preset rated values, the system start judgment result is determined to be successful start.
The method comprises the steps that whether a flexible direct system is successfully started to a steady state or not is judged through whether active output data and reactive output data reach a rated level and are stable, specifically, whether the active output data and the reactive output data comprise data such as active and reactive levels measured by a transmitting and receiving end, new energy output and the like, whether a fan or a photovoltaic unit is stably started and stably operates or not is judged, if the fan or the photovoltaic unit fails to start, a new energy station model is modified and adjusted, and whether a grid structure is correct is checked; if the machine is started normally, recording is started from a preset time point, for example, recording is started 100ms before a fault, and recording data are obtained.
And further, taking real-time voltage and current data of a line fault corresponding measuring point in the wave recording data as initial input, selecting a fault corresponding calculation phase, performing full-cycle Fourier transform on a short-circuit current matrix by matching with a model simulation sampling frequency, and extracting to obtain a short-circuit current fundamental wave effective value.
As shown in fig. 5, determining protection sensitivity and operation coefficient corresponding to each fault point according to the effective value of the short-circuit current fundamental wave according to an embodiment of the present invention includes:
Step S41, determining the sensitivity corresponding to the protection action time window by utilizing a preset protection action time window;
step S42, if the sensitivity corresponding to the protection action time window is smaller than the preset sensitivity threshold value, determining the protection sensitivity corresponding to each fault point according to the effective value of the short-circuit current fundamental wave;
Step S43, according to the load data in the end-to-end monopole layer flexible-direct system model, determining the station load working condition corresponding to the load data;
and S44, if the action coefficient corresponding to the station load working condition is smaller than the preset action coefficient threshold value, determining the action coefficient corresponding to each fault point according to the effective value of the short-circuit current fundamental wave.
The sum of the protection action delay and the channel delay is taken as an action time window, and the minimum value of the sensitivity of the phase current differential protection high-constant value and the low-constant value in the time window and the minimum value of the sensitivity of the zero sequence current differential protection constant value are obtained through searching, so that whether the sensitivity meets a preset sensitivity threshold value or not is judged, for example, the preset sensitivity threshold value can be the requirement of related regulations/standards; if the sensitivity is not met, the sensitivity is recalculated after updating the fixed value according to the preset sensitivity threshold. Specifically, according to the effective value of the short-circuit current fundamental wave, the protection sensitivity corresponding to each fault point is determined.
Specifically, the protection action delay is a preset action time fixed value, and the channel delay is a preset inherent signal transmission delay.
Further, load data in the end-to-end monopole layer flexible-to-straight system model is utilized to judge whether the new energy station connected to the flexible-to-straight system is empty or not, if the new energy station is not empty, the ratio of the differential current to the braking current under the input is further calculated, and the action coefficient is checked, wherein the specific calculation mode adopts a conventional method and is not repeated here. And acquiring and marking the minimum action coefficient in the time window of the high fixed value and the low fixed value of the phase current differential protection by searching preset information, judging whether the action coefficient meets a preset action coefficient threshold value or not, wherein the preset action coefficient threshold value can be related regulations/standard requirements. If the motion coefficient is not satisfied, the motion coefficient is recalculated after updating the fixed value according to the phase preset motion coefficient threshold value. Specifically, according to the effective value of the short-circuit current fundamental wave, determining the action coefficient corresponding to each fault point.
In this embodiment, after the protection sensitivity and the action coefficient corresponding to each fault point are obtained, the protection adaptability result is obtained by using the protection sensitivity and the action coefficient corresponding to each fault point. Specifically, the protection adaptability result may be a table of sensitivity and action coefficient of each fault point under different types of faults.
In an embodiment of the present invention, fig. 6 is a schematic diagram of a basic architecture of a new energy station with flexible and straight access in the embodiment of the present invention. The four-terminal flexible direct-current ring network mainly has two main network topology modes of four-terminal operation and end-to-end operation, two receiving terminal stations are respectively used as a load station and a direct-current voltage-regulating converter station, and the two sending terminal stations are controlled by fixed frequency and fixed alternating-current voltage so as to ensure the stability of the frequency and the voltage of a new energy grid-connected system at the sending terminal alternating-current side.
In four-terminal flexible direct current transmission, two transmitting-terminal converter stations are not communicated and are respectively connected with corresponding receiving terminals. Relay protection adaptability refers to the adaptation of the fixed value and principle of the protection device to the corresponding system operation conditions (such as load change, system oscillation, non-full-phase operation, network structure change, various interferences and impacts, etc.), the corresponding fault properties, types, positions, etc. The full digital real-time simulation device of the power system is ADVANCED DIGITAL Power System Simulator, (ADPSS). Based on a high-performance cluster server, the multi-node structure and the high-speed local network of the cluster are utilized, a parallel computing technology is adopted to decompose the computing task, and the process is controlled in real time and synchronously.
In this embodiment, the simulation steps are as shown in fig. 7, and the specific process is as follows:
Step 1: building a four-terminal flexible direct-current ring network and an accessed new energy station model, and determining model parameters and control modes by depending on actual converter parameters of equipment providers; the model is a manufacturer packaging model, and model parameters and control modes are provided by equipment manufacturers.
Step 2: the fault current change conditions of the same fault type of the same transmitting-end converter station under different operation modes are compared, particularly, the simulation type single-phase earth fault under the multiple operation modes of single-pole four-terminal ring network, end-to-end, three-terminal and the like is respectively checked, the current effective value of the fault phase is compared, the operation mode with the minimum short-circuit current is selected for carrying out subsequent field station protection adaptability analysis, namely, sensitivity and action coefficient verification is carried out based on the end-to-end single-pole layer operation mode.
Step 3: based on the built end-to-end monopole layer flexible straight system model, whether the voltage of the new energy station access flexible straight line bus and the voltage level of the high-low voltage side of the main transformer in the field meet engineering requirements is confirmed under the steady state condition, after no errors, the new energy side, the middle point, the station side measuring point and the outer measuring point of the two side areas of the line are selected as fault points, the high-voltage side, the low-voltage side and the low-voltage bus of the station main transformer are selected as fault points in the field, and fault batch processing simulation is executed.
And comparing the waveform of the output simulation result with the actual engineering requirement, and measuring the voltage level to confirm the voltage level of the high-voltage side and the low-voltage side of the main transformer.
Step 4: and acquiring line, main transformer voltage and current data under all faults through preset fault points in the model, and sending data such as direct current voltage of a receiving end and the like to the photovoltaic active power output level of the fan.
Step 5: judging whether the flexible-direct system is successfully started to a steady state or not through whether the data such as the active and reactive power level and the new energy output measured by the transmitting and receiving end reach the rated level and are stable, and if the flexible-direct system is started to the steady state or not, modifying and adjusting the new energy model in the step 1 if the flexible-direct system is started to the steady state or not, and if the flexible-direct system is failed, checking whether the grid structure is correct or not, and particularly, adjusting the model to adjust the multiplication coefficient and the control module of the packaging model; if the machine is started normally, recording short-circuit current, related voltage and power data from 100ms before the fault, and recording the change process of each parameter in the step 4 after the fault, thereby obtaining a short-circuit current matrix.
Step 6: and taking real-time voltage and current data of a line fault corresponding measuring point as initial input, selecting a fault corresponding calculation phase, carrying out full-cycle Fourier transform on a short-circuit current matrix by matching with a simulation sampling frequency, extracting a short-circuit current fundamental wave effective value, and determining protection action conditions according to a used protection device principle.
The full-cycle Fourier transform is realized by using a program statement, and the basic principle is that a fundamental component and a frequency multiplication component are obtained after sine and cosine decomposition is carried out on a periodic function current/voltage signal according to a Fourier series. The principle of the protection device refers to protection logic action conditions and fixed values written into each device, and the action conditions and the protection actions are met.
Further, the constant sensitivity=differential current (the modulus of the sum of the current vectors on both sides of the line)/the protection setting value (obtained from a preset protection setting value list), and the action coefficient=differential current/braking current (the modulus of the difference of the current vectors on both sides of the line).
Step 7: and taking the sum of the protection action delay and the channel delay as an action time window, searching and acquiring the minimum value of the sensitivity of the high fixed value and the low fixed value of the phase current differential protection in the time window and the minimum value of the sensitivity of the fixed value of the zero sequence current differential protection, judging whether the sensitivity meets the requirements of related regulations/standards, if not, updating the fixed value according to the related requirements, and then recalculating the sensitivity.
The protection action delay comes from the fixed value of action time of the protection devices of different manufacturers on the circuit/main transformer installed by the different protection devices; the channel delay is the signal transmission delay inherent to the device. In addition, the fixed value is recalculated by the dispatch-related departments and then is delivered.
Step 8: judging whether the new energy station connected to the flexible and straight station is empty or not, if the new energy station is not empty, further calculating the ratio of the differential current to the braking current under the input, checking the action coefficient, obtaining and marking the minimum action coefficient in a time window with a high fixed value and a low fixed value of the differential protection of the phase current through searching, judging whether the action coefficient meets the requirements of relevant regulations/standards or not by the minimum action coefficient in the time window of the differential protection of the zero sequence current, and if the action coefficient does not meet the requirements, updating the fixed value and then recalculating the action coefficient according to the relevant requirements;
The empty load judgment is carried out from the model building part, whether the station model is included or not is judged, and the station-free model is empty load. In fig. 6, the soft direct current converter station refers to a station connected with a new energy field station in the end-to-end monopole layer model, the new energy field station (such as a fan and a photovoltaic) is an alternating current part, soft direct current is direct current transmission, and a 220 line is alternating current in the figure.
Step 9; and (3) outputting a protection adaptability analysis result according to the sensitivity and action coefficient results of each fault point after the fault in the step (3) after the protection sensitivity and action coefficient calculation is finished. Specifically, the protection adaptability analysis result is a table of sensitivity and action coefficients of each fault point under different types of faults
The method has the advantages that the ADPSS can be applied to fault simulation of the access flexible and straight new energy field station in real time in electromagnetic transient precision, real-time simulation and fault batch processing calculation of the four-end ring network flexible and straight net frame are realized, transient characteristics of the access flexible and straight new energy field station subjected to disturbance at different positions in a line and a field can be effectively simulated, whether the system is unstable or not is judged, and meanwhile, various parameter change conditions of the system after faults occur are recorded. Aiming at the fault point of the new energy station which is connected with the soft straight, based on the system simulation data under the electromagnetic transient precision, whether the minimum value of the protection sensitivity and the action coefficient in the action time window meets the requirements or not is calculated, so that the checksum optimization of the protection fixed value is realized.
Fig. 8 is a schematic structural diagram of a protection adaptability determining device for a new energy station according to an embodiment of the present invention, where the device includes:
The system model module 10 is used for carrying out fault current change processing by utilizing a pre-constructed new energy station model under different preset operation modes to obtain an end-to-end monopole layer flexible-to-straight system model;
The fault simulation module 20 is configured to perform fault simulation processing on preset fault points by using an end-to-end monopole layer flexible-to-straight system model, so as to obtain fault simulation data corresponding to each fault point;
the current matrix module 30 is configured to perform a system start-up determination according to the fault simulation data, and perform a wave recording process according to a preset time point to obtain a short-circuit current matrix if the obtained system start-up determination result is that the start-up is successful;
A short-circuit current module 40, configured to perform full-cycle fourier transform on the short-circuit current matrix to obtain a short-circuit current fundamental wave effective value;
The adaptive result module 50 is configured to determine protection sensitivity and action coefficient corresponding to each fault point according to the effective value of the short-circuit current fundamental wave, and obtain a protection adaptive result by using the protection sensitivity and action coefficient corresponding to each fault point.
As an embodiment of the present invention, as shown in fig. 9, the system model module 10 includes:
The fault current unit 11 is configured to perform single-phase ground fault simulation on the same fault type of the same converter station by using a new energy station model built in advance under different preset operation modes, so as to obtain fault current change data;
And a system model unit 12, configured to determine an end-to-end unipolar layer flexible-to-straight system model corresponding to the minimum short-circuit current by using the fault current variation data.
As an embodiment of the present invention, as shown in fig. 10, the current matrix module 30 includes:
The output data unit 31 is configured to determine whether the active output data and the reactive output data reach a preset rated value according to the active output data and the reactive output data in the fault simulation data;
the start-up judging unit 32 is configured to determine that the system start-up judging result is successful if the active output data and the reactive output data both reach the preset rated values.
As shown in fig. 11, the adaptive result module 50 includes, as an embodiment of the present invention:
A time window unit 51, configured to determine a sensitivity corresponding to the protection action time window by using a preset protection action time window;
the sensitivity unit 52 is configured to determine, if the sensitivity corresponding to the protection action time window is less than the preset sensitivity threshold, the protection sensitivity corresponding to each fault point according to the effective value of the short-circuit current fundamental wave;
the load data unit 53 is configured to determine a station load condition corresponding to load data according to the load data in the end-to-end monopole layer flexible-direct system model;
And the action coefficient unit 54 is configured to determine an action coefficient corresponding to each fault point according to the effective value of the short-circuit current fundamental wave if the action coefficient corresponding to the station load working condition is less than the preset action coefficient threshold.
Based on the same application conception as the protection adaptability determination method of the new energy station, the invention also provides a protection adaptability determination device of the new energy station. The principle of solving the problem of the protection adaptability determining device of the new energy station is similar to that of the protection adaptability determining method of the new energy station, so that the implementation of the protection adaptability determining device of the new energy station can be referred to the implementation of the protection adaptability determining method of the new energy station, and repeated parts are omitted.
According to the invention, by carrying out fault simulation processing on the new energy station model, fault simulation and protection adaptability checking are considered, and effective simulation and analysis on the fault of the new energy station which is connected with the flexible direct control station are realized, so that a feasible basis is provided for flexible direct control protection and policy optimization research.
The invention also provides an electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the above method when executing the program.
The invention also provides a computer program product comprising computer programs/instructions which when executed by a processor implement the steps of the above method.
The present invention also provides a computer readable storage medium storing a computer program for executing the above method.
As shown in fig. 12, the electronic device 600 may further include: a communication module 110, an input unit 120, an audio processor 130, a display 160, a power supply 170. It is noted that the electronic device 600 need not include all of the components shown in fig. 12; in addition, the electronic device 600 may further include components not shown in fig. 12, to which reference is made to the related art.
As shown in fig. 12, the central processor 100, also sometimes referred to as a controller or operational control, may include a microprocessor or other processor device and/or logic device, which central processor 100 receives inputs and controls the operation of the various components of the electronic device 600.
The memory 140 may be, for example, one or more of a buffer, a flash memory, a hard drive, a removable media, a volatile memory, a non-volatile memory, or other suitable device. The information about failure may be stored, and a program for executing the information may be stored. And the central processor 100 can execute the program stored in the memory 140 to realize information storage or processing, etc.
The input unit 120 provides an input to the central processor 100. The input unit 120 is, for example, a key or a touch input device. The power supply 170 is used to provide power to the electronic device 600. The display 160 is used for displaying display objects such as images and characters. The display may be, for example, but not limited to, an LCD display.
The memory 140 may be a solid state memory such as Read Only Memory (ROM), random Access Memory (RAM), SIM card, or the like. But also a memory which holds information even when powered down, can be selectively erased and provided with further data, an example of which is sometimes referred to as EPROM or the like. Memory 140 may also be some other type of device. Memory 140 includes a buffer memory 141 (sometimes referred to as a buffer). The memory 140 may include an application/function storage 142, the application/function storage 142 for storing application programs and function programs or a flow for executing operations of the electronic device 600 by the central processor 100.
The memory 140 may also include a data store 143, the data store 143 for storing data, such as contacts, digital data, pictures, sounds, and/or any other data used by the electronic device. The driver storage 144 of the memory 140 may include various drivers of the electronic device for communication functions and/or for performing other functions of the electronic device (e.g., messaging applications, address book applications, etc.).
The communication module 110 is a transmitter/receiver 110 that transmits and receives signals via an antenna 111. A communication module (transmitter/receiver) 110 is coupled to the central processor 100 to provide an input signal and receive an output signal, which may be the same as in the case of a conventional mobile communication terminal.
Based on different communication technologies, a plurality of communication modules 110, such as a cellular network module, a bluetooth module, and/or a wireless local area network module, etc., may be provided in the same electronic device. The communication module (transmitter/receiver) 110 is also coupled to a speaker 131 and a microphone 132 via an audio processor 130 to provide audio output via the speaker 131 and to receive audio input from the microphone 132 to implement usual telecommunication functions. The audio processor 130 may include any suitable buffers, decoders, amplifiers and so forth. In addition, the audio processor 130 is also coupled to the central processor 100 so that sound can be recorded locally through the microphone 132 and so that sound stored locally can be played through the speaker 131.
It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The principles and embodiments of the present invention have been described in detail with reference to specific examples, which are provided to facilitate understanding of the method and core ideas of the present invention; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in accordance with the ideas of the present invention, the present description should not be construed as limiting the present invention in view of the above.
Claims (7)
1. A method for determining protection adaptability of a new energy station, the method comprising:
Under different preset operation modes, performing fault current change processing by utilizing a new energy station model constructed in advance to obtain an end-to-end monopole layer flexible-to-straight system model;
performing fault simulation processing on preset fault points by using the end-to-end monopole layer flexible-to-straight system model to obtain fault simulation data corresponding to each fault point;
Performing system starting judgment according to the fault simulation data, and performing wave recording processing according to a preset time point to obtain a short-circuit current matrix if the obtained system starting judgment result is that the starting is successful;
performing full-cycle Fourier transform on the short-circuit current matrix to obtain a short-circuit current fundamental wave effective value;
According to the effective value of the short-circuit current fundamental wave, determining protection sensitivity and action coefficient corresponding to each fault point, and obtaining a protection adaptability result by utilizing the protection sensitivity and action coefficient corresponding to each fault point;
Under different preset operation modes, performing fault current change processing by using a pre-built new energy station model, and obtaining an end-to-end monopole layer flexible-to-straight system model comprises the following steps:
under different preset operation modes, single-phase grounding fault simulation is carried out on the same fault type of the same converter station by utilizing a new energy station model constructed in advance, so as to obtain fault current change data;
determining an end-to-end monopole layer flexible-to-straight system model corresponding to the minimum short-circuit current by utilizing the fault current change data;
wherein, according to the effective value of the short-circuit current fundamental wave, determining protection sensitivity and action coefficient corresponding to each fault point comprises:
Determining the sensitivity corresponding to a protection action time window by using a preset protection action time window;
If the sensitivity corresponding to the protection action time window is smaller than a preset sensitivity threshold value, determining the protection sensitivity corresponding to each fault point according to the short-circuit current fundamental wave effective value;
determining a station load working condition corresponding to load data according to the load data in the end-to-end monopole layer flexible-direct system model;
and if the action coefficient corresponding to the station load working condition is smaller than a preset action coefficient threshold value, determining the action coefficient corresponding to each fault point according to the short-circuit current fundamental wave effective value.
2. The method of claim 1, wherein making a system start-up determination based on the fault simulation data comprises:
Judging whether the active output data and the reactive output data reach a preset rated value or not according to the active output data and the reactive output data in the fault simulation data;
And if the active output data and the reactive output data reach the preset rated values, determining that the system start judgment result is that the start is successful.
3. A protection adaptability determining apparatus for a new energy station, the apparatus comprising:
The system model module is used for carrying out fault current change processing by utilizing a pre-constructed new energy station model under different preset operation modes to obtain an end-to-end monopole layer flexible-to-straight system model;
the fault simulation module is used for performing fault simulation processing on preset fault points by using the end-to-end monopole layer flexible-to-straight system model to obtain fault simulation data corresponding to each fault point;
the current matrix module is used for carrying out system starting judgment according to the fault simulation data, and if the obtained system starting judgment result is that the starting is successful, carrying out wave recording processing according to a preset time point to obtain a short-circuit current matrix;
The short-circuit current module is used for carrying out full-cycle Fourier transform on the short-circuit current matrix to obtain a short-circuit current fundamental wave effective value;
The adaptive result module is used for determining the protection sensitivity and the action coefficient corresponding to each fault point according to the short-circuit current fundamental wave effective value, and obtaining a protection adaptive result by utilizing the protection sensitivity and the action coefficient corresponding to each fault point;
wherein the system model module comprises:
The fault current unit is used for carrying out single-phase earth fault simulation on the same fault type of the same converter station by utilizing a new energy station model constructed in advance under different preset operation modes to obtain fault current change data;
the system model unit is used for determining an end-to-end monopole layer flexible-to-straight system model corresponding to the minimum short circuit current by utilizing the fault current change data;
Wherein the adaptive result module comprises:
the time window unit is used for determining the sensitivity corresponding to the protection action time window by utilizing a preset protection action time window;
The sensitivity unit is used for determining the protection sensitivity corresponding to each fault point according to the effective value of the short-circuit current fundamental wave if the sensitivity corresponding to the protection action time window is smaller than a preset sensitivity threshold value;
the load data unit is used for determining the station load working condition corresponding to the load data according to the load data in the end-to-end monopole layer flexible-direct system model;
And the action coefficient unit is used for determining the action coefficient corresponding to each fault point according to the effective value of the short-circuit current fundamental wave if the action coefficient corresponding to the station load working condition is smaller than a preset action coefficient threshold value.
4. The apparatus of claim 3, wherein the current matrix module comprises:
the output data unit is used for judging whether the active output data and the reactive output data reach a preset rated value according to the active output data and the reactive output data in the fault simulation data;
And the starting judging unit is used for determining that the system starting judging result is successful in starting if the active output data and the reactive output data reach the preset rated values.
5. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the method of any of claims 1 to 2 when executing the computer program.
6. A computer readable storage medium, characterized in that the computer readable storage medium stores a computer program for executing the method of any one of claims 1 to 2.
7. A computer program product comprising computer programs/instructions which, when executed by a processor, implement the steps of the method of any one of claims 1 to 2.
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