CN118214031A - Broadband measurement system for photovoltaic power station - Google Patents
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Abstract
The invention discloses a broadband measurement system for a photovoltaic power station, which is applied to an integrated monitoring system of the photovoltaic power station and comprises a broadband measurement analysis substation and a broadband measurement device; the broadband measurement analysis substation is positioned at a station control layer in the integrated monitoring system of the photovoltaic power station; the system is respectively connected with a dispatching center and a broadband measurement device in an integrated monitoring system of the photovoltaic power station and is used for executing data receiving, file calling, file data analysis and dispatching forwarding data and file transmission; the broadband measuring device is positioned on a spacer layer in the integrated monitoring system of the photovoltaic power station; the functions of PMU, measurement and control and power quality devices are integrated, and the functions of the existing data concentrator and data communication gateway are integrated, so that the broadband multi-frequency signal is subjected to unified acquisition, classification processing, subscription as required and frequency division transmission. The broadband signal measuring device aims at the broadband characteristic of the power electronic power system signal, can meet the broadband signal measuring requirement of the power grid, and effectively solves the measuring problem of the broadband signal.
Description
Technical Field
The invention relates to the technical field of photovoltaic power generation, in particular to a broadband measurement system for a photovoltaic power station.
Background
Currently, to cope with global climate change, environmental pollution, energy strategy and the like, countries around the world are actively pushing low-carbonization, clean and sustainable transformation of energy systems. The energy source structure is realized, and the energy source structure is embodied as electric energy substitution and cleaning substitution. The novel power system taking the new energy as a main body is constructed, huge pulling action is generated on the wind power and photovoltaic field, and the wind power and the photovoltaic enter a multiplication stage.
However, as the non-water renewable capability such as wind power, photovoltaic and the like is connected into the power system, the permeability ratio of the non-water renewable capability is continuously improved, the future power system faces a plurality of new challenges, particularly the problem of space-time uncertainty caused by the non-water renewable energy source intermittence and high-ratio power electronization caused by a grid connection mode, the stability of various parameters which are mainly based on electromechanical dynamics in the traditional power system, including the stability of a power angle, voltage and frequency, can be changed, each link of the source network charge storage presents a high power electronization characteristic, electromagnetic oscillation with oscillation frequency changing in a wider range is caused by interaction between power electronic equipment and the power network, and broadband oscillation phenomenon appears successively, so that the equipment safety and the power network operation are endangered.
In addition, with the increasing application of the high-voltage direct-current transmission technology, the new technologies such as large-scale and distributed new energy sources, the FACTS technology and the like, the power grid structure is changed greatly; meanwhile, various nonlinear and sensitive power electronic devices also show an increasing trend in a power grid; the change of the power grid structure and the electric equipment makes the disturbance phenomenon of the power grid more and more frequent, and meanwhile, the problems of inter-harmonic waves, higher harmonic waves and the like are also brought, and the trend of a wide frequency domain is presented. However, the existing measurement technology is only aimed at signals in the power frequency range, and is difficult to deal with the acquisition and processing of broadband signals.
Therefore, there is a need to improve the monitoring capability of the power grid for disturbance components with different frequencies and reduce the running risk of the power grid. Aiming at the measurement requirement of broadband, a new broadband measurement device is developed to realize the measurement of broadband signals.
Disclosure of Invention
In view of the above, the invention provides a broadband measurement system for a photovoltaic power station, which can solve the signal measurement problem in a wide frequency domain. Aiming at the broadband characteristics of the power electronic power system signals, a broadband measurement technology system adapting to the development requirements of the power system measurement and monitoring technology is provided, the integration of various measurement devices of a transformer substation is promoted while the broadband signal measurement requirements of a power grid continuously emerging are met, and the system structure of the transformer substation is further optimized.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
the invention provides a broadband measurement system for a photovoltaic power station, which is applied to an integrated monitoring system of the photovoltaic power station, and comprises a broadband measurement analysis substation and a broadband measurement device;
The broadband measurement analysis substation is positioned at a station control layer in the integrated monitoring system of the photovoltaic power station; the system is respectively connected with a dispatching center and a broadband measurement device in the integrated monitoring system of the photovoltaic power station and is used for executing data receiving, file calling, file data analysis and dispatching forwarding data and file transmission;
The broadband measurement device is positioned at a spacer layer in the integrated monitoring system of the photovoltaic power station; the functions of PMU, measurement and control and power quality devices are integrated, and the functions of the traditional PDC data concentrator and the data communication gateway are integrated, so that the broadband multi-frequency signal is subjected to unified acquisition, classification processing, subscription as required and frequency division transmission.
Further, the broadband measurement device includes:
the acquisition module is used for uniformly acquiring sampling frequencies required by the current protection, measurement and control, PMU and metering device and also taking the quality of electric energy and the acquisition of power electronic higher harmonic signals into consideration; unified acquisition is carried out according to 512 points/cycle;
The classifying processing module is used for classifying and calculating the sampled data according to different application requirements;
The on-demand subscription module is used for providing original data, preprocessing data and analysis result data for other devices according to the fact that the broadband measurement device has the original data acquired at high frequency and the calculation data after calculation processing, and meanwhile, harmonic source positioning and intelligent alarm realization diagnosis result information can be carried out by combining with the calculation data of the broadband measurement device;
The frequency division transmission module is used for carrying out frequency conversion transmission according to external requirements by the broadband measurement device.
Furthermore, the acquisition module is also used for acquiring sampling data with reduced frequency in an interpolation mode, so that uniform acquisition of signals is realized while the sampling precision is not reduced.
Further, the classification processing module is specifically used for focusing on 13 th harmonic signals in the power frequency range corresponding to steady state measurement of the measurement and control device; the PMUs corresponding to dynamic measurement devices focus on the measurement of fundamental signals and require automatic filtering of other inter-harmonic and higher harmonic signals; calculating a value of 50 th harmonic or more corresponding to the power quality; and for the subsynchronous oscillation signals, the frequency spectrum analysis of the signals in the frequency bands of 2.5-45Hz and 55-100Hz is carried out.
Further, the frequency division transmission module is specifically configured to perform frequency conversion transmission according to a required sampling frequency based on original sampling data; for the measurement data, the transmission frequency of the data can be dynamically adjusted according to the external subscription requirement; and for the same type of data, according to the preset condition, the data is transmitted at low frequency in normal operation, and the transmission frequency is increased when a fault occurs, so that variable frequency transmission is realized.
Further, the broadband measurement analysis substation includes:
The data transmission module is used for realizing the transmission of broadband measurement data through different transmission protocols based on different ports of the broadband measurement device; the integrated monitoring system of the intelligent substation can be effectively compatible with the existing integrated monitoring system of the intelligent substation by transmitting fundamental wave measured values of power frequency through GB/T26865.2 and transmitting steady-state measured data through IEC61850 standard.
Further, the broadband measurement analysis substation further includes:
the file storage module is used for storing real-time measurement data in a file mode; the method can call and store the transient wave recording file and the continuous wave recording file on the broadband measuring device; XML files can be generated and stored based on the diagnostic parse structure.
Further, the broadband measurement analysis substation further includes:
the data preprocessing and analyzing module is used for waveform display of the wave record file, can analyze inter-harmonic frequency spectrum, has optional frequency resolution, has the statistical analysis function of harmonic, current, inter-voltage harmonic amplitude and oscillation frequency data, and supports spectrum analysis.
Further, the broadband measurement analysis substation further includes:
The real-time alarm module is used for realizing alarm grade classification and alarm real-time display through the alarm event grade configuration and recording the related information of continuous harmonic alarm; and the alarm event history query function is used for using the alarm function and the alarm event history query function.
Further, the broadband measurement analysis substation further includes:
The wave recording analysis module is used for realizing three-dimensional spectrum analysis and display, limit crossing, oscillation disturbance event statistics, harmonic/inter-harmonic distribution rule statistics and subsynchronous/supersynchronous oscillation signal frequency band statistics according to the built-in wave recording analysis tool.
Further, the broadband measurement analysis substation further includes:
and the visual display module is used for visually displaying the management state of the plant stations, the state of the server system, the alarm trend, the harmonic distortion rate ranking and the power change.
Compared with the prior art, the invention discloses a broadband measurement system for a photovoltaic power station, which is applied to an integrated monitoring system of the photovoltaic power station and comprises a broadband measurement analysis substation and a broadband measurement device; the broadband measurement analysis substation is positioned at a station control layer in the integrated monitoring system of the photovoltaic power station; the system is respectively connected with a dispatching center and a broadband measurement device in an integrated monitoring system of the photovoltaic power station and is used for executing data receiving, file calling, file data analysis and dispatching forwarding data and file transmission; the broadband measuring device is positioned on a spacer layer in the integrated monitoring system of the photovoltaic power station; the integrated power management unit (Power Management Unit, PMU), the functions of measurement and control and power quality devices, and the functions of the existing data concentrator (phasordata concentrator, PDC) and the data communication gateway are integrated, so that the integrated power management unit is used for uniformly collecting, classifying, subscribing and frequency-dividing transmission of broadband multi-frequency signals according to requirements.
Has the following advantages:
(1) The problem of wide frequency domain signal measurement is solved: aiming at the broadband characteristic of the power electronic power system signal, the system can meet the broadband signal measurement requirement of the power grid, and effectively solves the measurement problem of the broadband signal.
(2) Facilitating system integration: the integration of various measuring devices of the transformer substation is promoted, the system structure of the transformer substation is optimized, and the monitoring efficiency and the overall performance of the system are improved.
(3) And realizing data transmission and analysis: the broadband measurement analysis substation is connected with the dispatching center and the broadband measurement device, can perform functions of data receiving, file calling, data analysis and the like, and is beneficial to effectively transmitting data and carrying out real-time analysis.
(4) Integrated multifunctional: the broadband measuring device integrates the functions of a PMU, measurement and control and power quality device, and also comprises the functions of a PDC data concentrator and a data communication gateway, so that unified acquisition, classification processing and transmission of broadband multi-frequency signals are realized, and the intelligent and comprehensive performances of the system are improved.
(5) And (3) improving the power grid operation risk management: by improving the monitoring capability of the power grid to disturbance components with different frequencies, the system is beneficial to reducing the running risk of the power grid and guaranteeing the stability and safety of the power system.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.
Fig. 1 is an access schematic diagram of a broadband measurement system for a photovoltaic power station provided by the invention.
Fig. 2 is a schematic diagram of a specific scenario of the broadband measurement system for a photovoltaic power station provided by the present invention.
Fig. 3 is a functional block diagram of a broadband measurement device according to the present invention.
Fig. 4 is a functional block diagram of a broadband measurement analysis substation according to the present invention.
Detailed Description
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.
The intelligent transformer substation is used as a power transformation node of the whole power grid system, so that the functions of whole-network data acquisition, measurement, control and protection are achieved, and the broadband measurement related to the invention is researched in the range of the intelligent transformer substation. Meanwhile, novel power electronic equipment such as a unified power flow controller (Unifiedpower flowcontroller, UPFC), a Static synchronous compensator (Static SynchronousCompensator, STATCOM) and a controllable series compensation capacitor (Thyristor Controlled SeriesCompensation, TCSC) are continuously put into operation, disturbance phenomena such as harmonic interference and subsynchronous oscillation of a power grid are more frequent, the harmonic wave of the power grid shows a trend of a wide frequency domain, and the monitoring capability of the power grid on disturbance components of different frequencies is required to be improved, so that the running risk of the power grid is reduced.
The traditional power grid mainly comprises inductive elements and synchronous generators, the voltage output by the synchronous generators is almost perfect sine wave, when the number of converters of power electronic equipment is small, the traditional power grid can maintain the operation characteristic of the traditional power grid, the traditional power grid generally shows ideal voltage source characteristics, at the moment, the converters mainly interact with the power grid, and the influence of the converters on the power grid characteristics is weak. The core technology of new energy power generation and direct current transmission is based on the electric energy conversion and control of power electronic devices, so that the power grid has obvious power electronization characteristics. Today, with the rapid increase in grid-connected inverter permeability, the "grid-by-grid" interactions between the converter and the grid, and the interactions between the converter and the converter, are becoming more and more intense, more and more frequent, and more complex, the assumption that the grid is considered an ideal voltage source is no longer established. The influence of power electronic equipment on a power system is changed from variable quantity to variable quality, and the power system gradually goes from power frequency to broadband.
Therefore, research and application of a key technology for wide-area synchronous measurement of a power system broadband are urgently needed to be developed, and support is provided for power grid monitoring and control under the environment that power electronic equipment is accessed in a large quantity.
The embodiment of the invention discloses a broadband measurement system for a photovoltaic power station, which is applied to an integrated monitoring system of the photovoltaic power station and comprises a broadband measurement analysis substation (such as a battlefield storage analysis device and other telemechanical transmission equipment in FIG. 1) and a broadband measurement device, wherein the broadband measurement system is shown by referring to FIGS. 1-2;
as shown in fig. 1, the broadband measurement and analysis substation is located at a station control layer in an integrated monitoring system of a photovoltaic power station; the system is respectively connected with a dispatching center and a broadband measurement device in an integrated monitoring system of the photovoltaic power station and is used for executing data receiving, file calling, file data analysis and dispatching forwarding data and file transmission;
the broadband measuring device is positioned on a spacer layer in the integrated monitoring system of the photovoltaic power station; the functions of PMU, measurement and control and power quality devices are integrated, and the functions of the traditional PDC data concentrator and the data communication gateway are integrated, so that the broadband multi-frequency signal is subjected to unified acquisition, classification processing, subscription as required and frequency division transmission.
The broadband measurement device of the spacer layer can integrate the functions of devices such as PMU, measurement and control, power quality and the like; the station domain storage equipment or other remote control equipment of the station control layer can integrate the functions of the existing PDC data concentrator, the shutdown of the data communication network and the like. However, from the practical engineering application, in order not to affect the normal operation of various measurement devices in the existing measurement system, a broadband measurement system architecture is designed on the basis of the existing integrated monitoring system, as shown in fig. 2. Namely, a broadband measurement analysis substation and a broadband measurement device are newly added according to the current mode that different measurement system frameworks are set by the reference photovoltaic transformer substation according to different services.
The broadband measurement analysis substation supports a GB/T26865.2 communication protocol, and can communicate with the broadband measurement device and the scheduling master station system respectively through the GB/T26865.2 protocol. The method is based on the data receiving, file calling, file data analysis and the scheduling forwarding data and file transmission of the Linux operating system executing device. The YXH-BSD-201 broadband measurement, storage and analysis device comprises a network port 1, a network port 2 and a broadband measurement device which are directly connected, and a network port 3 and a network port 4 which are respectively connected with a dispatching plane through a dispatching data network.
The broadband measurement analysis substation simultaneously supports more than 8 scheduling master stations to be simultaneously accessed, supports more than 4 broadband measurement devices to be simultaneously accessed, and calls files with the suffix of three formats of. Hdr, & cfg and & dat from the broadband devices at regular time. The system mainly comprises a system configuration function, a broadband device interaction function, a scheduling master station interaction function, a self-starting function and a file storage function.
As can be seen from fig. 2, the broadband measurement device is implemented by adopting the general technical route of "unified acquisition, classification processing, subscription on demand and frequency division transmission".
As shown in fig. 3, the broadband measurement apparatus includes: the system comprises an acquisition module, a classification processing module, an on-demand subscription module and a frequency division transmission module,
1. Unified collection: the method is characterized in that besides the sampling frequency required by the current protection, measurement and control, PMU and metering device, the acquisition requirements of signals such as power quality, power electronic higher harmonics and the like are considered, various requirements at the present stage are integrated, and the highest sampling frequency is required to 256 points/cycle (12.8 kHz). The signal frequency range covered by the sampling frequency is 0-6.4kHz, and the sampling requirement of 9kHz frequency cannot be met, so that the sampling frequency of the broadband multi-frequency sampling device needs to reach 18kHz in order to meet the sampling requirement of 9kHz frequency, and the sampling frequency is uniformly acquired according to 512 points/cycle (25.6 kHz) in consideration of the compatibility of the sampling frequency to the existing measuring system, so that the measuring requirement of all devices can be met. For devices not requiring such high sampling frequency, the sampling data with reduced frequency can be obtained by interpolation, so that uniform acquisition of signals can be realized without reducing sampling precision.
For example, by analyzing actual operation data of the north disc Jiang Guangfu power station and simulating scheduling operation data, and combining actual situations of energy production, the long-term, day-ahead and real-time scheduling rules of the north disc river basin under different situations are summarized. The synchronous precision of the sampling data receiving process is analyzed, the Lagrange interpolation algorithm and the sampling time deviation are combined for analysis, and the method for adaptively adjusting the interpolation time is provided, so that the interpolation error can be effectively reduced, and the focus of the research is on the relation between the interpolation time and the synchronous error. The synchronous method for receiving and processing the sampled data is researched, and the composition of delay time of each stage of the data sampling link is mainly analyzed.
2. Classification treatment: the pointer carries out classified calculation on the sampled data according to different application requirements, the steady state measurement corresponding to the measurement and control device still focuses on 13 th harmonic signals in the power frequency range, the PMU corresponding to the dynamic measurement device still focuses on the measurement of fundamental wave signals, and at the moment, the application needs to automatically filter other inter-harmonic and higher harmonic signals; corresponding to the power quality, values of 50 or even higher harmonics can be calculated; and for the subsynchronous oscillation signals, the frequency spectrum analysis of the signals with the frequency ranges of 2.5-45Hz and 55-100Hz can be carried out. Of course, the classification process is implemented in stages and steps according to the development requirements of the power grid itself, although numerous application functions are implemented.
3. Subscription as needed: the broadband measurement device has high-frequency collected original data and calculated and processed calculation data, meanwhile, intelligent advanced application modules such as harmonic source positioning, intelligent alarming and the like can be combined with the calculation data to realize diagnosis result information, and original data, preprocessing data and analysis result data can be provided for other devices.
4. Frequency division transmission: the broadband multi-frequency unified measuring device can perform variable frequency transmission according to external requirements. For the original sampling data, variable frequency transmission can be carried out according to the required sampling frequency; for the measurement data, the transmission frequency of the data can be dynamically adjusted according to the external subscription requirement. For the same type of data, the low-frequency transmission can be performed in normal operation according to preset conditions, and the frequency of transmission is increased when faults occur, so that variable-frequency transmission is realized.
Referring to fig. 4, the broadband measurement analysis substation includes: the system comprises a data transmission module, a file storage module, a data preprocessing and analysis module, a real-time alarm module, a wave recording analysis module and a visual display module.
(1) And (3) data transmission: the transmission of broadband measurement data is realized through different transmission protocols by different ports of the broadband measurement analysis substation, the transmission is realized through GB/T26865.2 (IEE C37.118) for fundamental wave measurement values of power frequency, and the transmission is realized through IEC61850 standard for steady-state measurement data, so that the broadband measurement analysis substation can be effectively compatible with the existing measurement technology system architecture, and is beneficial to popularization and application.
(2) File storage function: the broadband measurement analysis substation can store real-time measurement data from the broadband measurement device in a file manner; the method can call and store the transient wave recording file and the continuous wave recording file on the broadband measuring device; the XML file can be generated and stored according to the diagnosis analysis structure, and the master station can conveniently retrieve.
(3) Data preprocessing and analysis function: the waveform display can be carried out on the wave record file, the inter-harmonic frequency spectrum can be analyzed, the frequency resolution is optional, the statistical analysis function of data sent by the broadband measuring device is provided, and the maximum value, the minimum value and the average value of 2-50 times of harmonic waves in 5 minutes can be counted; the device has the statistical analysis function of maximum value, minimum value and average value of the harmonic amplitude between current and voltage within 5 minutes; collecting the frequency and amplitude of 10 dominant components of secondary/super synchronous oscillation in real time, and statistically analyzing the oscillation frequency with the largest occurrence number and the occurrence number of the frequency within 5 minutes; the frequency spectrum analysis is supported by the harmonic wave and inter-harmonic wave analysis function of single channel and multiple channels within 2500 Hz.
Among these, for harmonic analysis, there are two ways:
Mode 1: during asynchronous sampling, the dense harmonic signals of the power system can generate the problems of spectrum leakage and fence effect during discrete Fourier transform analysis, so that the mixed convolution window obtained by convolution operation of the rectangular window and the cosine window can analyze and give out performance indexes such as main lobe width, attenuation rate and the like of the novel mixed convolution window function.
Mode 2: the harmonic analysis method based on chebyshev window multipoint correction can be realized by analyzing the actual operation data of the photovoltaic power station and simulating and scheduling operation data. The method achieves the aim of inhibiting side lobes through phase rotation, multipoint correction and other processing on the basis of limiting the width of the main lobe, and can realize high-precision identification of harmonic signal parameters containing inter-harmonics. Simulation analysis is carried out on classical harmonic signals and power dense harmonic signals, and calculation verification is carried out on noise signals and harmonic signals containing inter-harmonics.
(4) And (3) real-time monitoring: the broadband measurement analysis substation not only realizes functions of on-line monitoring of equipment states, real-time data monitoring, off-line file calling and the like, but also realizes real-time monitoring of key data such as harmonic waves, inter-harmonic waves, low-frequency oscillation and the like aiming at the problems of harmonic interference, subsynchronous oscillation and the like of the new energy plant station, comprehensively grasps the variation trend of the key data and effectively improves the monitoring level of the new energy plant station on the electric energy quality.
(5) Real-time alarm: the broadband measurement analysis substation realizes alarm level classification and real-time alarm display by configuring alarm event levels, and records related information of continuous harmonic alarms such as frequency and content of harmonic out-of-limit; in addition, the broadband measurement analysis substation realizes the functions of alarming for system resource use and alarming event history inquiry.
The real-time alarm threshold is set as follows:
a. the low-frequency oscillation alarm signal, when the frequency range of the oscillation power is 0.1-2.5Hz, the Boolean signal uploading rate can reach 1 time/second so as to meet the requirement of real-time alarm of the power grid oscillation;
b. The secondary synchronous oscillation alarm signal, when the frequency range of the oscillation power is 2.5-45Hz, the Boolean signal, the up-feed rate can reach 1 time/second, so as to meet the requirement of the real-time alarm of the power grid oscillation;
c. and when the frequency range of the oscillation power is above 55Hz, the uploading speed can reach 1 time/second so as to meet the requirement of real-time warning of the power grid oscillation.
In order to realize real-time and broadband monitoring of the whole network by the regulation and control center, unified modeling and real-time transmission of the broadband measurement data are needed. In addition, the phasor, analog quantity and Boolean quantity data are all required to be synchronously collected and sent with a time scale, so that the regulating and controlling master station can obtain the information of the whole network system-time section. The time scale of the power frequency data needs to reach the resolution of whole 10ms, and the time scale of the harmonic and inter-harmonic data needs to reach the resolution of whole second. From the above analysis, various broadband measurement data have different data types, number of measurement points and transmission rate requirements. In order to realize unified real-time transmission of the data, the applicability of the existing mainstream communication protocol to broadband measurement data transmission needs to be studied, the most suitable communication protocol is selected, and the communication protocol is supplemented or expanded as required. The current protocols related to real-time transmission of synchronous phasor belt time marks at home and abroad mainly comprise an IEC61850 general communication protocol, an IEC 61850-90-5 special phasor communication protocol and an IEEE C37.118 synchronous phasor communication protocol.
(6) Wave recording analysis: by the aid of the built-in wave recording analysis tool, three-dimensional spectrum analysis and display, out-of-limit and oscillation disturbance event statistics, harmonic/inter-harmonic distribution rule statistics and sub/super synchronous oscillation signal frequency band statistics can be achieved.
(7) Visual display: the homepage provides visual display of data such as factory station management state, server system state, alarm trend, harmonic distortion rate ranking, power change and the like.
The broadband measurement system also has the following advantages:
high-speed synchronous sampling, wherein the rate is more than or equal to 12.8kHz; the requirements of broadband oscillation real-time monitoring and alarming can be met; the alarm grade classification and the real-time alarm display are realized, and the related information of continuous harmonic alarms such as the frequency and the content of harmonic out-of-limit are recorded; the secondary/super-synchronous oscillation frequency of 2.5-45 Hz and 55-95 Hz can be covered; the current and voltage dominant components of 0-2500 Hz, the dominant components of current, voltage and instantaneous power, the current and voltage 50 subharmonic and inter-harmonic subgroups can be transmitted; the three-dimensional spectrum analysis and the display of the wave recording file can be realized.
The broadband measurement system for the photovoltaic power station provided by the invention realizes effective measurement of broadband signals in the photovoltaic power station, such as power frequency signals, higher harmonic signals, inter-harmonic signals and the like, and scientifically improves photovoltaic dispatching effect.
In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. The broadband measurement system for the photovoltaic power station is characterized by being applied to an integrated monitoring system of the photovoltaic power station, and comprises a broadband measurement analysis substation and a broadband measurement device;
The broadband measurement analysis substation is positioned at a station control layer in the integrated monitoring system of the photovoltaic power station; the system is respectively connected with a dispatching center and a broadband measurement device in the integrated monitoring system of the photovoltaic power station and is used for executing data receiving, file calling, file data analysis and dispatching forwarding data and file transmission;
The broadband measurement device is positioned at a spacer layer in the integrated monitoring system of the photovoltaic power station; the functions of PMU, measurement and control and power quality devices are integrated, and the functions of the traditional PDC data concentrator and the data communication gateway are integrated, so that the broadband multi-frequency signal is subjected to unified acquisition, classification processing, subscription as required and frequency division transmission.
2. The broadband measurement system for a photovoltaic power plant of claim 1, wherein the broadband measurement device comprises:
the acquisition module is used for uniformly acquiring sampling frequencies required by the current protection, measurement and control, PMU and metering device and also taking the quality of electric energy and the acquisition of power electronic higher harmonic signals into consideration; unified acquisition is carried out according to 512 points/cycle;
The classifying processing module is used for classifying and calculating the sampled data according to different application requirements;
The on-demand subscription module is used for providing original data, preprocessing data and analysis result data for other devices according to the fact that the broadband measurement device has the original data acquired at high frequency and the calculation data after calculation processing, and meanwhile, harmonic source positioning and intelligent alarm realization diagnosis result information can be carried out by combining with the calculation data of the broadband measurement device;
The frequency division transmission module is used for carrying out frequency conversion transmission according to external requirements by the broadband measurement device.
3. The broadband measurement system for the photovoltaic power station according to claim 2, wherein the acquisition module is further configured to acquire sampling data of reduced frequency by interpolation, so as to ensure uniform acquisition of signals without reducing sampling accuracy.
4. The broadband measurement system for a photovoltaic power station according to claim 2, wherein the classification processing module is specifically configured to focus on 13 th harmonic signals in a power frequency range corresponding to steady state measurement of the measurement and control device; the PMUs corresponding to dynamic measurement devices focus on the measurement of fundamental signals and require automatic filtering of other inter-harmonic and higher harmonic signals; calculating a value of 50 th harmonic or more corresponding to the power quality; and for the subsynchronous oscillation signals, the frequency spectrum analysis of the signals in the frequency bands of 2.5-45Hz and 55-100Hz is carried out.
5. The broadband measurement system for a photovoltaic power station according to claim 2, wherein the frequency division transmission module is specifically configured to perform frequency conversion transmission according to a required sampling frequency based on original sampling data; for the measurement data, the transmission frequency of the data can be dynamically adjusted according to the external subscription requirement; and for the same type of data, according to the preset condition, the data is transmitted at low frequency in normal operation, and the transmission frequency is increased when a fault occurs, so that variable frequency transmission is realized.
6. The broadband measurement system for a photovoltaic power plant of claim 1, wherein the broadband measurement analysis substation comprises:
the file storage module is used for storing real-time measurement data in a file mode; the method can call and store the transient wave recording file and the continuous wave recording file on the broadband measuring device; XML files can be generated and stored based on the diagnostic parse structure.
7. The photovoltaic power plant-oriented broadband measurement system of claim 6, wherein the broadband measurement analysis substation further comprises:
the data preprocessing and analyzing module is used for waveform display of the wave record file, can analyze inter-harmonic frequency spectrum, has optional frequency resolution, has the statistical analysis function of harmonic, current, inter-voltage harmonic amplitude and oscillation frequency data, and supports spectrum analysis.
8. The photovoltaic power plant-oriented broadband measurement system of claim 6, wherein the broadband measurement analysis substation further comprises:
The real-time alarm module is used for realizing alarm grade classification and alarm real-time display through the alarm event grade configuration and recording the related information of continuous harmonic alarm; and the alarm event history query function is used for using the alarm function and the alarm event history query function.
9. The photovoltaic power plant-oriented broadband measurement system of claim 6, wherein the broadband measurement analysis substation further comprises:
The wave recording analysis module is used for realizing three-dimensional spectrum analysis and display, limit crossing, oscillation disturbance event statistics, harmonic/inter-harmonic distribution rule statistics and subsynchronous/supersynchronous oscillation signal frequency band statistics according to the built-in wave recording analysis tool.
10. The broadband measurement system for a photovoltaic power plant of claim 2, wherein the broadband measurement analysis substation further comprises:
and the visual display module is used for visually displaying the management state of the plant stations, the state of the server system, the alarm trend, the harmonic distortion rate ranking and the power change.
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