Method and device for tracking broadband oscillation wide-area propagation path of new energy field grid-connected system

Abstract

The invention provides a new energy field grid-connected system broadband oscillation wide-area propagation path tracking method and device, and the method comprises the steps: firstly obtaining an electrical main wiring diagram of a transformer substation, numbering incoming and outgoing lines, and recording the rated voltage and capacity of the incoming and outgoing lines; and monitoring harmonic voltage and current of the high-voltage bus and the low-voltage bus of the transformer substation, carrying out fast Fourier analysis, and judging whether oscillation occurs or not. If oscillation occurs, the concerned oscillation spectrum range and harmonic wave type are determined, and the sampling frequency is determined. Then, a sampling instruction is issued, voltage and current data of all lines are collected, and per-unit processing is carried out; and performing Fourier series analysis on the data to obtain a harmonic spectrogram. And finally, determining an oscillation propagation path in combination with the main wiring diagram, the operation mode and the spectrogram so as to quickly position disturbance sources, quantify responsibilities of multiple disturbance sources and improve system stability.

Description

Technical Field

[0001] The present invention relates to the field of new energy grid-connected technology, and in particular to a method and device for tracking a broadband oscillation wide-area propagation path of a new energy grid-connected system. Background Art

[0002] The connection of multiple renewable energy power plants to the grid through power electronic devices will not only cause low-frequency oscillation problems in the power system, but also induce sub- / super-synchronous oscillation problems in the power system. In recent years, oscillation accidents have been reported in multiple renewable energy grid-connected systems. The interaction between the oscillation generated by the renewable energy power station and the AC transmission network will cause the oscillation energy to further propagate across voltage levels along the AC transmission network to the AC main grid, causing the power equipment in the AC transmission network to also oscillate, seriously threatening the safe and stable operation of renewable energy power stations and power systems. Different types of renewable energy power stations are connected to the grid at different voltage levels, and the propagation path of the oscillation is complex. In areas rich in renewable energy resources, some frequency oscillations have occurred. After being connected from the low voltage level, they are transmitted to the high-voltage transmission network after multiple voltage level conversions, resulting in large oscillations in the UHV DC transmission system and causing serious accidents such as the locking and tripping of the protection device. Therefore, it is of great significance to track the propagation path of broadband oscillations in renewable energy power generation systems.

[0003] Power system oscillation is the specific manifestation of the propagation of disturbance energy in the power network. Research on power grid oscillation caused by energy propagation is currently mainly focused on the field of electromechanical transients in power systems. However, the morphological characteristics, influencing factors, and internal mechanisms of the broadband oscillations of renewable energy grid-connected systems caused by the application of a high proportion of power electronic devices in AC systems of different voltage levels are still unclear. At the same time, renewable energy power plants have multiple outgoing lines, so for the collection substations of large renewable energy power plants, it is equivalent to having multiple oscillation disturbance sources. At present, most of the methods for dividing the responsibilities of multiple oscillation disturbance sources are completed on the basis of the instantaneous values ​​of voltage and current, which is inconsistent with the current status of the daily power quality monitoring system that mainly provides statistical values ​​such as voltage and current effective values. Therefore, there is an urgent need for a method for tracking the wide-area propagation path of broadband oscillations in renewable energy power plants. Summary of the invention

[0004] In view of this, the present invention provides a method and device for tracking a wide-band oscillation wide-area propagation path of a new energy field grid-connected system to solve at least one of the above-mentioned problems.

[0005] In order to achieve the above object, the present invention adopts the following scheme:

[0006] According to a first aspect of the present invention, a method for tracing the wide-band oscillation wide-area propagation path of a new energy field grid-connected system is provided, the method comprising: obtaining the electrical main wiring diagrams of all substations in the multi-new energy field grid-connected system, and numbering all incoming and outgoing lines of each substation, obtaining the rated voltage and capacity of each incoming and outgoing line, and forming a line parameter database, wherein the parameter database includes the number of each incoming and outgoing line and the corresponding rated voltage and capacity; performing harmonic voltage and current monitoring and fast Fourier analysis on the high and low voltage buses of all substations in the multi-new energy field grid-connected system, and judging whether an oscillation accident occurs according to the harmonic amplitude; in response to the occurrence of an oscillation accident, determining the oscillation spectrum range and harmonic type that need to be paid attention to, and according to the The oscillation spectrum range is used to determine the line harmonic sampling frequency; an oscillation sampling instruction is issued to all substations in the multi-new energy field grid-connected system, the voltage and current data of all incoming and outgoing lines are collected in the same time period, and the collected voltage and current data are normalized according to the rated voltage and capacity in the line parameter database; Fourier series analysis is performed on the normalized data to obtain the harmonic spectrum diagram of the voltage and current of the incoming and outgoing lines of each substation in the same time period; combined with the electrical main connection diagram and operation mode of each substation in the multi-new energy field grid-connected system, and the harmonic spectrum diagram of the voltage and current of the incoming and outgoing lines of each substation in the same time period, the propagation path of the main oscillation in the new energy grid-connected system is determined.

[0007] As an embodiment of the present invention, the above method performs harmonic voltage and current monitoring and fast Fourier analysis on the high and low voltage buses of all substations in the multi-new energy field grid-connected system, and judges whether an oscillation accident occurs according to the harmonic amplitude, including: continuously collecting high and low voltage bus voltage and current data of all substations in the multi-new energy field grid-connected system, and performing fast Fourier transform to obtain the harmonic spectrum of the bus voltage and current; judging whether an oscillation accident occurs in the multi-new energy field grid-connected system according to whether the harmonic amplitude in the harmonic spectrum of the bus voltage and current exceeds the standard.

[0008] As an embodiment of the present invention, the above method determines the oscillation spectrum range and harmonic wave type that need to be paid attention to, and determines the line harmonic sampling frequency based on the oscillation spectrum range, including: determining the oscillation spectrum range and harmonic wave type that need to be paid attention to based on the spectrum range of the bus's excessive harmonic amplitude; determining the line harmonic sampling frequency based on the oscillation spectrum range that needs to be paid attention to in the bus.

[0009] As an embodiment of the present invention, the above method determines the propagation path of the main oscillation in the new energy grid-connected system, including: determining the propagation path of the frequency oscillation in the new energy grid-connected system according to the oscillation amplitude of the same frequency oscillation in the inlet and outlet lines of different substations; determining the position of the main oscillation disturbance source according to the propagation path of the same frequency oscillation in different lines; quantifying the harmonic responsibility of each of the multiple harmonic disturbance sources according to the normalized amplitude of the voltage and current of each oscillation disturbance source in the same time period.

[0010] As an embodiment of the present invention, the multi-new energy field grid-connected system in the above method includes multiple new energy power generation sites, a collection substation interconnected with the new energy power generation sites, and a substation interconnected with the collection substation.

[0011] As an embodiment of the present invention, the inlet and outlet lines in the above method include all the inlet and outlet lines on the low-voltage side and the high-voltage side of the substation, as well as reactive compensation and filter feeder lines.

[0012] According to a second aspect of the present invention, there is provided a device for tracking the wide-band oscillation wide-area propagation path of a new energy field grid-connected system, the device comprising: a database construction unit, for obtaining the electrical main wiring diagrams of all substations in the multi-new energy field grid-connected system, and numbering all inlet and outlet lines of each substation, obtaining the rated voltage and capacity of each inlet and outlet line, and forming a line parameter database, wherein the parameter database includes the number of each inlet and outlet line and the corresponding rated voltage and capacity; an oscillation accident judgment unit, for performing harmonic voltage and current monitoring and fast Fourier analysis on the high and low voltage buses of all substations in the multi-new energy field grid-connected system, and judging whether an oscillation accident occurs according to the harmonic amplitude; a spectrum and harmonic determination unit, for determining the oscillation spectrum range and harmonic type that need to be paid attention to when an oscillation accident occurs, and judging whether an oscillation accident occurs according to the oscillation spectrum range, determine the line harmonic sampling frequency; a sampling instruction issuing unit, used to issue oscillation sampling instructions to all substations in the multi-new energy field grid-connected system; a per-unit processing unit, used to collect voltage and current data of all inbound and outbound lines in the same time period, and per-unit process the collected voltage and current data according to the rated voltage and capacity in the line parameter database; a spectrum acquisition unit, used to perform Fourier series analysis on the per-unit processed data, and obtain the harmonic spectrum diagram of the voltage and current of the inbound and outbound lines of each substation in the same time period; a propagation path determination unit, used to determine the propagation path of the main oscillation in the new energy grid-connected system in combination with the electrical main wiring diagram and operation mode of each substation in the multi-new energy grid-connected system, and the harmonic spectrum diagram of the voltage and current of the inbound and outbound lines of each substation in the same time period.

[0013] As an embodiment of the present invention, the above-mentioned oscillation accident judgment unit is specifically used to: continuously collect high and low voltage bus voltage and current data of all substations in the multi-new energy field grid-connected system, and perform fast Fourier transform to obtain the harmonic spectrum of the bus voltage and current; judge whether an oscillation accident occurs in the multi-new energy field grid-connected system based on whether the harmonic amplitude in the harmonic spectrum of the bus voltage and current exceeds the standard.

[0014] As an embodiment of the present invention, the above-mentioned spectrum and harmonic determination unit is specifically used to: determine the oscillation spectrum range and harmonic type that need to be paid attention to according to the spectrum range of the bus harmonic amplitude exceeding the standard; determine the line harmonic sampling frequency according to the oscillation spectrum range that needs to be paid attention to in the bus.

[0015] As an embodiment of the present invention, the above-mentioned propagation path determination unit determines the propagation path of the main oscillation in the new energy grid-connected system, including: determining the propagation path of the frequency oscillation in the new energy grid-connected system according to the oscillation amplitude of the same frequency oscillation in the inlet and outlet lines of different substations; determining the position of the main oscillation disturbance source according to the propagation path of the same frequency oscillation in different lines; quantifying the harmonic responsibility of each of the multiple harmonic disturbance sources according to the normalized amplitude of the voltage and current of each oscillation disturbance source in the same time period.

[0016] As an embodiment of the present invention, the above-mentioned multiple renewable energy field grid-connected system includes multiple renewable energy power generation sites, a collection substation interconnected with the renewable energy power generation sites, and a substation interconnected with the collection substation.

[0017] As an embodiment of the present invention, the above-mentioned inlet and outlet lines include all the inlet and outlet lines on the low-voltage side and the high-voltage side of the substation, as well as reactive compensation and filter feeder lines.

[0018] According to a third aspect of the present invention, there is provided an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0019] According to a fourth aspect of the present invention, there is provided a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the above method when executed by a processor.

[0020] The method and device for tracking the wide-band oscillation and wide-area propagation path of the new energy field grid-connected system proposed in the present invention can quickly determine the propagation paths of harmonics of different frequencies in the power system and accurately locate the location of the harmonic disturbance source. It is also possible to quantify the responsibility of the oscillation disturbance in multiple collection lines and determine the main oscillation disturbance source lines, which makes up for the deficiency of the existing technology that the harmonic responsibility is divided based on the instantaneous values ​​of voltage and current, and is consistent with the current status of the daily power quality monitoring system mainly providing statistical values ​​such as the effective value of voltage and current. In addition, by quickly locating the disturbance source and quantifying the responsibility, more targeted measures can be taken to suppress the oscillation, ensure the safe and stable operation of the new energy power station and the power system, and avoid serious accidents such as the locking and tripping of the protection device due to oscillation in the ultra-high voltage direct current transmission system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0022] Figure 1 It is a flow chart of a method for tracking a wide-band oscillation wide-area propagation path of a new energy field grid-connected system provided in an embodiment of the present application;

[0023] Figure 2 It is a schematic diagram of the main electrical wiring diagram of the multi-new energy field grid-connected system provided in the embodiment of the present application;

[0024] Figure 3 is a schematic diagram of a flow chart of determining a propagation path of a main oscillation in a new energy grid-connected system provided by an embodiment of the present invention;

[0025] Figure 4 It is a structural schematic diagram of a broadband oscillation wide-area propagation path tracking device for a new energy field grid-connected system provided in an embodiment of the present application;

[0026] Figure 5 It is a structural schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0027] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0028] like Figure 1The figure is a flow chart of a method for tracking a wide-band oscillation wide-area propagation path of a new energy field grid-connected system provided by an embodiment of the present application. The method comprises the following steps:

[0029] Step S101: Obtain the main electrical connection diagrams of all substations in the multi-renewable energy field grid-connected system, and number all incoming and outgoing lines of each substation, obtain the rated voltage and capacity of each incoming and outgoing line, and form a line parameter database, which includes the number of each incoming and outgoing line and the corresponding rated voltage and capacity.

[0030] Obtain the main electrical wiring diagram of all substations in the multi-renewable energy field grid-connected system. This diagram should include the connection mode of the internal equipment of the substation and the connection relationship with the external lines. Figure 2 The figure shows a schematic diagram of the main electrical connection diagram of a multi-renewable energy field grid-connected system. Preferably, in addition to obtaining the main electrical connection diagram, information such as voltage level and operation mode can also be obtained in this step.

[0031] After obtaining the main electrical wiring diagram, all incoming and outgoing lines of each substation are numbered to ensure that each line has a unique identifier for subsequent data analysis and path tracking. It should be noted that if a line connects two substations, the line uses the same number. This is because, in order to track the propagation path of oscillations in the power system, it is necessary to clearly identify and track the oscillation conditions on each line. If the same line connects two substations but uses different numbers, when analyzing the data, the oscillation data of the same line will be mistaken for the oscillation data of two different lines, resulting in path tracking errors and the inability to accurately determine the true propagation path of the oscillation and the final disturbance source location. Using the same number ensures that when analyzing data from different substations, the oscillation data on the same line can be associated, thereby accurately tracking the propagation path of the oscillation.

[0032] Then, the rated voltage and capacity of each incoming and outgoing line are obtained. These parameters will be used to standardize the collected voltage and current data.

[0033] Finally, the above information is integrated into a line parameter database, which should contain the number, rated voltage and rated capacity of each incoming and outgoing line for quick access and use.

[0034] Preferably, the multi-new energy field grid-connected system includes multiple new energy power generation sites, a collection substation interconnected with the new energy power generation sites, and a substation interconnected with the collection substation.

[0035] Preferably, the inlet and outlet lines include all the inlet and outlet lines on the low-voltage side and the high-voltage side of the substation, as well as reactive compensation and filter feeder lines.

[0036] Step S102: perform harmonic voltage and current monitoring and fast Fourier analysis on the high and low voltage buses of all substations in the multi-renewable energy field grid-connected system, and determine whether an oscillation accident occurs according to the harmonic amplitude.

[0037] The incoming and outgoing lines of a substation refer to the lines that connect the substation to the external lines, while the high and low voltage busbars refer to the busbars that connect different devices inside the substation. The incoming and outgoing lines are connected to the busbars, which in turn are connected to transformers, circuit breakers and other equipment. Therefore, monitoring the harmonic voltage and current of the busbar can more comprehensively reflect the harmonic situation inside the substation, not just the harmonic situation of the incoming and outgoing lines, so as to more accurately determine the occurrence and propagation path of oscillation accidents.

[0038] Preferably, in this step, harmonic voltage and current monitoring and fast Fourier analysis are performed on the high and low voltage buses of all substations in the multi-new energy field grid-connected system, and judging whether an oscillation accident occurs according to the harmonic amplitude can further include: continuously collecting high and low voltage bus voltage and current data of all substations in the multi-new energy field grid-connected system, and performing fast Fourier transform to obtain the harmonic spectrum of the bus voltage and current; judging whether an oscillation accident occurs in the multi-new energy field grid-connected system according to whether the harmonic amplitude in the harmonic spectrum of the bus voltage and current exceeds the standard, and when the harmonic amplitude exceeds the set threshold, it can be determined that an oscillation accident has occurred in the multi-new energy field grid-connected system.

[0039] Step S103: In response to the occurrence of an oscillation accident, determining an oscillation spectrum range and harmonic type that require attention, and determining a line harmonic sampling frequency according to the oscillation spectrum range.

[0040] Preferably, determining the oscillation spectrum range and harmonic type that need to be concerned in this step, and determining the line harmonic sampling frequency according to the oscillation spectrum range can further include: determining the oscillation spectrum range and harmonic type (such as interharmonics, harmonics) that need to be concerned according to the spectrum range of the busbar's excessive harmonic amplitude (such as low frequency band, medium frequency band or high frequency band); determining the line harmonic sampling frequency according to the oscillation spectrum range that needs to be concerned in the busbar. Selecting a suitable sampling frequency can ensure the accuracy of the analysis and minimize the amount of data collection and storage.

[0041] Step S104: sending oscillation sampling instructions to all substations in the multi-renewable energy field grid-connected system, collecting voltage and current data of all inbound and outbound lines in the same time period, and normalizing the collected voltage and current data according to the rated voltage and capacity in the line parameter database.

[0042] Send oscillation sampling instructions to all substations in the multi-renewable energy field grid-connected system to ensure that all substations collect data in the same time period for synchronous analysis. Then collect the voltage and current data of all incoming and outgoing lines in the same time period, and store the collected data according to the line number. Then, standardize the collected voltage and current data according to the rated voltage and capacity in the line parameter database, that is, convert the voltage and current data of different lines into a unified standard value for comparison and analysis.

[0043] Step S105: Perform Fourier series analysis on the normalized data to obtain harmonic spectrum diagrams of voltage and current of the inlet and outlet lines of each substation in the same time period.

[0044] Fourier series analysis is performed on the normalized data to convert the normalized voltage and current data in the time domain into harmonic spectrum in the frequency domain. The harmonic spectrum of the voltage and current of each substation inlet and outlet line in the same time period is obtained. The horizontal axis of the harmonic spectrum is the oscillation spectrum of interest, and the vertical axis is the amplitude of each frequency oscillation.

[0045] Step S106: Determine the propagation path of the main oscillation in the renewable energy grid-connected system by combining the electrical main connection diagram and operation mode of each substation in the multi-renewable energy grid-connected system and the harmonic spectrum diagram of the voltage and current of the inlet and outlet lines of each substation in the same time period.

[0046] Preferably, Figure 3 As shown, in this step, determining the propagation path of the main oscillation in the new energy grid-connected system may further include:

[0047] Step S301: determining a propagation path of the frequency oscillation in the new energy grid-connected system according to the oscillation amplitude of the same frequency oscillation in the inlet and outlet lines of different substations.

[0048] Based on the difference in oscillation amplitude of the same frequency oscillation in the lines entering and leaving different substations, the propagation path of the frequency oscillation in the renewable energy grid-connected system is determined, because the oscillation signal usually has a larger amplitude on the line close to the disturbance source and gradually attenuates along the propagation path.

[0049] Step S302: determining the location of the main oscillation disturbance source according to the propagation paths of oscillations of the same frequency on different lines.

[0050] According to the propagation paths of the same-frequency oscillations in different lines determined in step S301, the line or substation with the largest oscillation amplitude is found, thereby determining the location of the main oscillation disturbance source.

[0051] Step S303: quantifying the harmonic responsibilities of the multiple harmonic disturbance sources according to the normalized amplitudes of the voltage and current of each oscillation disturbance source in the same time period.

[0052] In the case of multiple harmonic disturbance sources, the harmonic responsibilities of each of the multiple harmonic disturbance sources are quantified according to the normalized amplitudes of the voltage and current of each oscillation disturbance source in the same time period. For example, the responsibility of each disturbance source can be evaluated according to the proportion of harmonic energy contributed by it.

[0053] Finally, combined with the electrical wiring diagrams of the new energy power plant aggregation substation, the substations interconnected with the aggregation substation, and the harmonic spectrum diagrams of the incoming and outgoing lines of each substation, according to the normalized amplitudes of the same frequency harmonics in the incoming and outgoing lines of different substations, it is determined on which lines the harmonics are propagated, and then the lines containing the same harmonic transmission are connected to obtain the propagation path diagram of harmonics of different frequencies.

[0054] From the above, it can be seen that the wide-band oscillation wide-area propagation path tracking method of the new energy field grid-connected system proposed in the present invention can quickly determine the propagation paths of harmonics of different frequencies in the power system and accurately locate the position of the harmonic disturbance source. It is also possible to quantify the responsibility of the oscillation disturbance in multiple collection lines and determine the main oscillation disturbance source lines, which makes up for the deficiency of the existing technology that the harmonic responsibility is divided based on the instantaneous values ​​of voltage and current, and is consistent with the current status of the daily power quality monitoring system mainly providing statistical values ​​such as the effective value of voltage and current. In addition, by quickly locating the disturbance source and quantifying the responsibility, more targeted measures can be taken to suppress the oscillation, ensure the safe and stable operation of the new energy power station and the power system, and avoid serious accidents such as the locking and tripping of the protection device due to oscillation in the ultra-high voltage direct current transmission system.

[0055] like Figure 4 The structure diagram of a wide-band oscillation wide-area propagation path tracking device for a new energy field grid-connected system provided by an embodiment of the present application is shown, and the device includes: a database construction unit 410, an oscillation accident judgment unit 420, a spectrum and harmonic determination unit 430, a sampling instruction issuing unit 440, a normalization processing unit 450, a spectrum map acquisition unit 460 and a propagation path determination unit 470, which are sequentially connected. Among them:

[0056] The database construction unit 410 is used to obtain the main electrical connection diagrams of all substations in the multi-renewable energy field grid-connected system, and to number all incoming and outgoing lines of each substation, to obtain the rated voltage and capacity of each incoming and outgoing line, and to form a line parameter database, which includes the number of each incoming and outgoing line and the corresponding rated voltage and capacity.

[0057] The oscillation accident judgment unit 420 is used to perform harmonic voltage and current monitoring and fast Fourier analysis on the high and low voltage buses of all substations in the multi-renewable energy field grid-connected system, and judge whether an oscillation accident occurs according to the harmonic amplitude.

[0058] The spectrum and harmonic determination unit 430 is used to determine the oscillation spectrum range and harmonic type that need to be paid attention to when an oscillation accident occurs, and determine the line harmonic sampling frequency according to the oscillation spectrum range.

[0059] The sampling instruction sending unit 440 is used to send oscillation sampling instructions to all substations in the multi-renewable energy field grid-connected system.

[0060] The per-unit processing unit 450 is used to collect the voltage and current data of all incoming and outgoing lines in the same time period, and perform per-unit processing on the collected voltage and current data according to the rated voltage and capacity in the line parameter database.

[0061] The spectrum acquisition unit 460 is used to perform Fourier series analysis on the normalized data to obtain the harmonic spectrum of the voltage and current of the inlet and outlet lines of each substation in the same time period.

[0062] The propagation path determination unit 470 is used to determine the propagation path of the main oscillation in the renewable energy grid-connected system by combining the main electrical connection diagram and operation mode of each substation in the multi-renewable energy grid-connected system, and the harmonic spectrum diagram of the voltage and current of the incoming and outgoing lines of each substation in the same time period.

[0063] Preferably, the above-mentioned oscillation accident judgment unit 420 is specifically used for: continuously collecting high and low voltage bus voltage and current data of all substations in the multi-renewable energy field grid-connected system, and performing fast Fourier transform to obtain the harmonic spectrum of the bus voltage and current; judging whether an oscillation accident occurs in the multi-renewable energy field grid-connected system based on whether the harmonic amplitude in the harmonic spectrum of the bus voltage and current exceeds the standard.

[0064] Preferably, the spectrum and harmonic determination unit 430 is specifically used to: determine the oscillation spectrum range and harmonic type that need attention according to the spectrum range of the bus's excessive harmonic amplitude; determine the line harmonic sampling frequency according to the oscillation spectrum range that needs attention in the bus.

[0065] Preferably, the above-mentioned propagation path determination unit 470 determines the propagation path of the main oscillation in the new energy grid-connected system, including: determining the propagation path of the frequency oscillation in the new energy grid-connected system according to the oscillation amplitude of the same frequency oscillation in the lines entering and exiting different substations; determining the position of the main oscillation disturbance source according to the propagation path of the same frequency oscillation in different lines; quantifying the harmonic responsibility of each of the multiple harmonic disturbance sources according to the normalized amplitude of the voltage and current of each oscillation disturbance source in the same time period.

[0066] Preferably, the above-mentioned multi-new energy field grid-connected system includes multiple new energy power generation sites, a collection substation interconnected with the new energy power generation sites, and a substation interconnected with the collection substation.

[0067] Preferably, the above-mentioned inlet and outlet lines include all the inlet and outlet lines on the low-voltage side and the high-voltage side of the substation, as well as reactive compensation and filter feeder lines.

[0068] From the above, it can be seen that the broadband oscillation wide-area propagation path tracking device for the new energy field grid-connected system proposed in the present invention can quickly determine the propagation paths of harmonics of different frequencies in the power system and accurately locate the position of the harmonic disturbance source. It is also possible to quantify the responsibility of the oscillation disturbance in multiple collection lines and determine the main oscillation disturbance source lines, which makes up for the deficiency of the existing technology that the harmonic responsibility is divided based on the instantaneous values ​​of voltage and current, and is consistent with the current status of the daily power quality monitoring system mainly providing statistical values ​​such as the effective value of voltage and current. In addition, by quickly locating the disturbance source and quantifying the responsibility, more targeted measures can be taken to suppress the oscillation, ensure the safe and stable operation of the new energy power station and the power system, and avoid serious accidents such as the locking and tripping of the protection device due to oscillation in the ultra-high voltage direct current transmission system.

[0069] Figure 5 is a schematic diagram of an electronic device provided by an embodiment of the present invention. Figure 5 The electronic device shown is a general data processing device, which includes a general computer hardware structure, which includes at least a processor 801 and a memory 802. The processor 801 and the memory 802 are connected via a bus 803. The memory 802 is suitable for storing one or more instructions or programs executable by the processor 801. The one or more instructions or programs are executed by the processor 801 to implement the steps in the above-mentioned new energy field grid-connected system broadband oscillation wide-area propagation path tracking method.

[0070] The processor 801 may be an independent microprocessor or a collection of one or more microprocessors. Thus, the processor 801 executes the commands stored in the memory 802 to execute the method flow of the embodiment of the present invention as described above to realize the processing of data and the control of other devices. The bus 803 connects the above-mentioned multiple components together, and at the same time connects the above-mentioned components to the display controller 804 and the display device and the input / output (I / O) device 805. The input / output (I / O) device 805 may be a mouse, a keyboard, a modem, a network interface, a touch input device, a somatosensory input device, a printer, and other devices known in the art. Typically, the input / output (I / O) device 805 is connected to the system via an input / output (I / O) controller 806.

[0071] The memory 802 may store software components such as an operating system, a communication module, an interaction module, and an application program. Each of the modules and applications described above corresponds to a set of executable program instructions that implement one or more functions and methods described in the embodiments of the invention.

[0072] An embodiment of the present invention also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the above-mentioned method for tracking the wide-band oscillation wide-area propagation path of the new energy field grid-connected system are implemented.

[0073] From the above, it can be seen that the method and device for tracking the wide-band oscillation wide-area propagation path of the new energy field grid-connected system proposed in the present invention can quickly determine the propagation paths of harmonics of different frequencies in the power system and accurately locate the position of the harmonic disturbance source. It is also possible to quantify the responsibility of the oscillation disturbance in multiple collection lines and determine the main oscillation disturbance source lines, which makes up for the deficiency of the existing technology that the harmonic responsibility is divided based on the instantaneous values ​​of voltage and current, and is consistent with the current status of the daily power quality monitoring system mainly providing statistical values ​​such as the effective value of voltage and current. In addition, by quickly locating the disturbance source and quantifying the responsibility, more targeted measures can be taken to suppress the oscillation, ensure the safe and stable operation of the new energy power station and the power system, and avoid serious accidents such as the locking and tripping of the protection device due to oscillation in the ultra-high voltage direct current transmission system.

[0074] The preferred embodiments of the present invention are described above with reference to the accompanying drawings. Many features and advantages of these embodiments are clear from this detailed description, and therefore the claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. In addition, since many modifications and changes are easily conceivable to those skilled in the art, it is not intended to limit the embodiments of the present invention to the precise structure and operation illustrated and described, but all suitable modifications and equivalents falling within its scope may be covered.

[0075] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0076] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0077] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0078] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0079] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for tracking the wide-band oscillation wide-area propagation path of a new energy field grid-connected system, characterized in that: The method comprises: Obtain the electrical main wiring diagrams of all substations in the multi-renewable energy field grid-connected system, and number all inlet and outlet lines of each substation, obtain the rated voltage and capacity of each inlet and outlet line, and form a line parameter database, which includes the number of each inlet and outlet line and the corresponding rated voltage and capacity; Performing harmonic voltage and current monitoring and fast Fourier analysis on the high and low voltage buses of all substations in the multi-renewable energy field grid-connected system, and determining whether an oscillation accident occurs according to the harmonic amplitude; In response to an oscillation accident, determining an oscillation spectrum range and harmonic type that require attention, and determining a line harmonic sampling frequency based on the oscillation spectrum range; Sending oscillation sampling instructions to all substations in the multi-renewable energy field grid-connected system, collecting voltage and current data of all inbound and outbound lines in the same time period, and normalizing the collected voltage and current data according to the rated voltage and capacity in the line parameter database; Perform Fourier series analysis on the normalized data to obtain the harmonic spectrum of voltage and current of each substation's inlet and outlet lines in the same time period; Combined with the electrical main connection diagram and operation mode of each substation in the multi-new energy grid-connected system, as well as the harmonic spectrum diagram of the voltage and current of the inlet and outlet lines of each substation in the same time period, the propagation path of the main oscillation in the new energy grid-connected system is determined.

2. The method for tracking the wide-band oscillation wide-area propagation path of a new energy field grid-connected system according to claim 1, characterized in that: The harmonic voltage and current monitoring and fast Fourier analysis of the high and low voltage buses of all substations in the multi-renewable energy field grid-connected system, and judging whether an oscillation accident occurs according to the harmonic amplitude include: Continuously collect high and low voltage bus voltage and current data of all substations in the multi-renewable energy field grid-connected system, and perform fast Fourier transform to obtain the harmonic spectrum of the bus voltage and current; judge whether an oscillation accident occurs in the multi-renewable energy field grid-connected system based on whether the harmonic amplitude in the harmonic spectrum of the bus voltage and current exceeds the standard.

3. The method for tracking the wide-band oscillation wide-area propagation path of a new energy field grid-connected system according to claim 1, characterized in that: Determining the oscillation spectrum range and harmonic type that need to be paid attention to, and determining the line harmonic sampling frequency according to the oscillation spectrum range includes: According to the spectrum range of the busbar's excessive harmonic amplitude, determine the oscillation spectrum range and harmonic type that need to be paid attention to; according to the oscillation spectrum range that needs to be paid attention to in the busbar, determine the line harmonic sampling frequency.

4. The method for tracking the wide-band oscillation wide-area propagation path of a new energy field grid-connected system according to claim 1, characterized in that: The method for determining the propagation path of the main oscillation in the renewable energy grid-connected system includes: determining the propagation path of the frequency oscillation in the renewable energy grid-connected system according to the oscillation amplitude of the same frequency oscillation in the inlet and outlet lines of different substations; determining the position of the main oscillation disturbance source according to the propagation path of the same frequency oscillation in different lines; and quantifying the harmonic responsibility of each of the multiple harmonic disturbance sources according to the normalized amplitude of the voltage and current of each oscillation disturbance source in the same time period.

5. The method for tracking the wide-band oscillation wide-area propagation path of a new energy field grid-connected system as claimed in claim 1, characterized in that: The multi-new energy field grid-connected system includes a plurality of new energy power generation sites, a collection substation interconnected with the new energy power generation sites, and a substation interconnected with the collection substation.

6. The method for tracking the wide-band oscillation wide-area propagation path of a new energy field grid-connected system as claimed in claim 1, characterized in that: The inlet and outlet lines include all the inlet and outlet lines on the low-voltage side and the high-voltage side of the substation, as well as reactive compensation and filter feeder lines.

7. A device for tracking the wide-band oscillation and wide-area propagation path of a new energy field grid-connected system, characterized in that: The device comprises: A database construction unit is used to obtain the electrical main wiring diagrams of all substations in the multi-new energy field grid-connected system, and number all inlet and outlet lines of each substation, obtain the rated voltage and capacity of each inlet and outlet line, and form a line parameter database, which includes the number of each inlet and outlet line and the corresponding rated voltage and capacity; An oscillation accident judgment unit is used to perform harmonic voltage and current monitoring and fast Fourier analysis on the high and low voltage buses of all substations in the multi-renewable energy field grid-connected system, and judge whether an oscillation accident occurs according to the harmonic amplitude; A spectrum and harmonic determination unit, used to determine the oscillation spectrum range and harmonic type that need to be paid attention to when an oscillation accident occurs, and determine the line harmonic sampling frequency according to the oscillation spectrum range; A sampling instruction issuing unit, used for issuing oscillation sampling instructions to all substations in the multi-renewable energy field grid-connected system; A per-unit processing unit, used for collecting voltage and current data of all inbound and outbound lines in the same time period, and performing per-unit processing on the collected voltage and current data according to the rated voltage and capacity in the line parameter database; The spectrum acquisition unit is used to perform Fourier series analysis on the normalized data to obtain the harmonic spectrum of the voltage and current of the inlet and outlet lines of each substation in the same time period; The propagation path determination unit is used to determine the propagation path of the main oscillation in the renewable energy grid-connected system by combining the electrical main connection diagram and operation mode of each substation in the multi-renewable energy grid-connected system and the harmonic spectrum diagram of the voltage and current of the inlet and outlet lines of each substation in the same time period.

8. The broadband oscillation wide-area propagation path tracking device for a new energy field grid-connected system as claimed in claim 7, characterized in that: The oscillation accident judgment unit is specifically used for: Continuously collect high and low voltage bus voltage and current data of all substations in the multi-renewable energy field grid-connected system, and perform fast Fourier transform to obtain the harmonic spectrum of the bus voltage and current; judge whether an oscillation accident occurs in the multi-renewable energy field grid-connected system based on whether the harmonic amplitude in the harmonic spectrum of the bus voltage and current exceeds the standard.

9. The broadband oscillation wide-area propagation path tracking device for a new energy field grid-connected system as claimed in claim 7, characterized in that: The spectrum and harmonic determination unit is specifically used for: According to the spectrum range of the busbar's excessive harmonic amplitude, determine the oscillation spectrum range and harmonic type that need to be paid attention to; according to the oscillation spectrum range that needs to be paid attention to in the busbar, determine the line harmonic sampling frequency.

10. The broadband oscillation wide-area propagation path tracking device for a new energy field grid-connected system as claimed in claim 7, characterized in that: The propagation path determination unit determines the propagation path of the main oscillation in the new energy grid-connected system, including: determining the propagation path of the frequency oscillation in the new energy grid-connected system according to the oscillation amplitude of the same frequency oscillation in the inlet and outlet lines of different substations; determining the position of the main oscillation disturbance source according to the propagation path of the same frequency oscillation in different lines; quantifying the harmonic responsibility of each of the multiple harmonic disturbance sources according to the normalized amplitude of the voltage and current of each oscillation disturbance source in the same time period.

11. The broadband oscillation wide-area propagation path tracking device for a new energy field grid-connected system as claimed in claim 7, characterized in that: The multi-new energy field grid-connected system includes a plurality of new energy power generation sites, a collection substation interconnected with the new energy power generation sites, and a substation interconnected with the collection substation.

12. The broadband oscillation wide-area propagation path tracking device for a new energy field grid-connected system as claimed in claim 7, characterized in that: The inlet and outlet lines include all the inlet and outlet lines on the low-voltage side and the high-voltage side of the substation, as well as reactive compensation and filter feeder lines.

13. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

14. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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