Distributed Location Method, System, Device and Storage Medium for Power Grid Oscillation Source

Abstract

The present invention belongs to the field of power system automation, and discloses a distributed positioning method, system, device and storage medium for power grid low-frequency and broadband oscillation sources. The method includes: collecting synchronous phasor data, harmonic and inter-harmonic phasor data of each branch in substations, power plants and new energy collection stations; the devices in the power plants and substations calculate the low-frequency oscillation source positioning characteristic quantities by using the synchronous phasor data, and calculate the broadband oscillation source positioning characteristic quantities by using the harmonic and inter-harmonic phasor data; sending up the low-frequency oscillation source positioning characteristic quantities and the broadband oscillation source positioning characteristic quantities for wide-area oscillation source positioning of the power grid. In substations, power plants and new energy stations, taking each branch as a unit, the characteristic quantities for low-frequency oscillation and broadband oscillation positioning are calculated in-situ and distributed in real time, and the master stations such as the dispatching center can achieve fast positioning of the low-frequency and broadband oscillation sources according to the calculation results of the power plants and substations.

Description

Technical Field

[0001] The present invention belongs to the field of power system automation, and particularly relates to a method, system, device and storage medium for distributed positioning of power grid oscillation sources. Background Art

[0002] With the large-scale application of new energy technologies and AC / DC power transmission technologies, the proportion of power electronic devices in the power grid has been continuously increasing, injecting a large amount of harmonics and inter-harmonics, and interacting with the power grid to form oscillation phenomena from several Hz to several thousand Hz. The oscillation form has expanded from the original low-frequency oscillation mainly dominated by electromechanical transients to more complex broadband oscillations. Oscillations seriously affect the safe and stable operation of the power system. How to quickly and accurately locate the oscillation source is an important issue in power grid operation control and a long-term research hotspot in the academic community.

[0003] With the accelerating construction of the new power system, measurement devices such as broadband measurement devices and synchronized phasor measurement devices are increasingly widely used for the measurement and monitoring of the main grid and distribution network of the power system. When centralized processing of a large amount of synchronized phasor, harmonic, and inter-harmonic phasor measurement data is carried out at the dispatching master station for oscillation identification and oscillation source positioning, there are problems such as large data storage and operation pressure, and it is difficult to ensure the real-time performance of oscillation monitoring and positioning.

[0004] Currently, synchronized phasor measurement devices and measurement and control devices installed at the substation (such as substations, power plants, and new energy collection stations) measure synchronized phasor data such as fundamental wave voltage, current amplitude, phase angle, and power, as well as harmonic, inter-harmonic, and oscillation power phasor data, and real-time monitor low-frequency oscillations and broadband oscillation events. Currently, the oscillation source positioning function is mainly realized centrally at the master station such as WAMS, mainly including the positioning of low-frequency oscillation sources related to electromechanical transients. The positioning algorithm is mainly the transient energy flow algorithm based on synchronized phasors. The application of broadband oscillation source positioning is still in its infancy, mainly tracing the source through the magnitude and phase characteristics of the dominant components of harmonics and inter-harmonics. Summary of the Invention

[0005] Aiming at the problems and difficulties existing in the centralized monitoring and positioning of low-frequency and broadband oscillations at the master station, the present invention proposes a method, system, device and storage medium for distributed positioning of power grid oscillation sources. At the measurement data source end such as substations, power plants, and new energy collection stations, the characteristic quantities required for the monitoring and positioning of low-frequency and broadband oscillations are calculated in real time on-site for each branch, and the analysis results are sent to the master station to reduce the processing pressure of the master station and achieve the quick positioning of low-frequency and broadband oscillation sources.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for distributed positioning of power grid oscillation sources, which is applied to the substation end and includes:

[0008] Collect synchronous phasor, harmonic and inter-harmonic phasor data in units of busbars and branches;

[0009] Under the trigger of substation oscillation monitoring and alarming or commands issued by the master station, use synchronous phasors to locally calculate the low-frequency oscillation source location characteristic quantities, and use harmonic and inter-harmonic phasor data to calculate the wide-frequency oscillation source location characteristic quantities;

[0010] Upload the low-frequency oscillation source location characteristic quantities and wide-frequency oscillation source location characteristic quantities to the master station for the master station to perform distributed location of the power grid oscillation source.

[0011] In some embodiments of the present disclosure, the calculation of the low-frequency oscillation source location characteristic quantities using synchronous phasor data specifically includes:

[0012] The criterion for the substation to trigger low-frequency oscillation alarm is: within the set number of oscillations X osc , the average peak-to-valley difference of the fundamental active power P base fluctuation exceeds the alarm threshold P osc ;

[0013] After the substation device triggers a low-frequency oscillation alarm or receives a master station command, use the collected synchronous phasor data to start transient energy integration calculation in units of busbars and branches; when the low-frequency oscillation alarm is eliminated or the set integration duration T max_int is reached, the device ends the transient energy flow integration calculation;

[0014] The substation device performs transient energy integration curve fitting calculation in units of busbars and branches, with the integration start time as the origin, and outputs the low-frequency oscillation characteristic quantities of each bus i and branch j. The low-frequency oscillation characteristic quantities are the fitting slope k ij and intercept b ij .

[0015] In some embodiments of the present disclosure, the calculation method of the fundamental active power P base is:

[0016]

[0017] In formula (1), U a , I a , U b , I b , U c , I c are voltage and current synchronous phasors;

[0018] The substation device uses synchronous phasor data to calculate the transient energy integration of each bus i and branch j. The specific method is:

[0019] or

[0020] In formula (2), T max_int is the set integration duration, and E dis is the transient energy integration.

[0021] In some embodiments of the present disclosure, after the substation device triggers a low-frequency oscillation alarm or receives a master station command, if the low-frequency oscillation alarm has not been eliminated and the transient energy integration duration T max_int is reached, the slope k ij and the intercept b ij are fitted. Taking the current moment as T0, the transient energy integration and fitting are cyclically executed according to the integration duration T max_int until the low-frequency oscillation alarm is eliminated.

[0022] In some embodiments of the present disclosure, the distributed positioning of the power grid oscillation source refers to positioning the low-frequency oscillation source according to the power grid topology and the fitting parameters k ij and b ij of the transient energy integration curves of each branch sent from the substation side.

[0023] In some embodiments of the present disclosure, calculating the wide-frequency oscillation source positioning characteristic quantity by using harmonic and inter-harmonic phasor data specifically includes:

[0024] The substation device calculates the instantaneous active power sampling sequence based on the voltage and current sampling values u a , i a , u b , i b , u c , i c , extracts the dominant oscillation power component through the FFT algorithm according to formula (3), and the amplitude P fk and frequency f k of the oscillation power component;

[0025] {P f1 ...P fn} = FFT{u a i a + u b i b + u c i c} (3)

[0026] The substation device takes the bus branch as a unit. Within the set time T sso , when the substation device monitors that the amplitude of any wide-frequency oscillation power component P fk continuously exceeds the set alarm threshold P sso , a wide-frequency oscillation alarm is triggered.

[0027] In some embodiments of the present disclosure, after the wide-frequency oscillation alarm is triggered, the substation device calculates the set frequency deviation f at each calculation cycleoffset Track the n oscillation power components with the largest amplitudes. When the frequency f of the oscillation power component k and the oscillation frequency f measured last time lastk satisfy Equation (4), it is determined as the same oscillation power component, and f lastk is updated to f k , and the tracking of the next cycle f k is executed;

[0028] f lastk - f offset < f k < f lastk + f offset (4)

[0029] Further, according to the frequency f of the oscillation power component P fk and the fundamental frequency f k , match the harmonic or interharmonic phasors of the phase voltage and current, as shown in Equation (5); the voltage and current phasors obtained by matching are: U base , I Xfk- , U Xfk- , I Xfk+ ; the subscript k represents the phase types A, B, and C; Xfk+ ;

[0030] f base - f k - f offset < f YX < f base - f k + f offset or f base + f k - f offset < f YX < f base + f k + f offset (5).

[0031] In some embodiments of the present disclosure, the substation device calculates the generated active power P Xfk_r according to Equation (6), and calculates the wide - frequency oscillation power component P fk of the total active power P fk_r generated on the branch;

[0032]

[0033] P fk_r = P Afk_r + P Bfk_r + P Cfk_r (7)

[0034] Calculate the cumulative energy according to the set number of cycles N When E Nfk ≤E set- When the oscillation power component P of busbar i branch j is fk The magnitude is marked as negative. Nfk ≥E set+ When the oscillation power component P fk The magnitude is marked as positive.

[0035] The oscillation power amplitude after the marker is transmitted to the master station: a characteristic quantity for locating the broadband oscillation source.

[0036] In some embodiments of the present disclosure, the distributed positioning of the power grid oscillation source refers to the plant station device calculating the amplitude and positive and negative signs of each branch and each oscillation power component, and the master station locates the oscillation source in the network based on the broadband oscillation source positioning feature sent by the substation.

[0037] A distributed positioning device for a power grid oscillation source, applied to a power plant, comprises:

[0038] Acquisition module, used to collect synchronous phasor, harmonic and interharmonic phasor data based on busbar and branch;

[0039] The calculation module is used to calculate the low-frequency oscillation source positioning characteristic quantity on-site using the synchronized phasor when triggered by the plant oscillation monitoring alarm or the command issued by the master station, and calculate the broadband oscillation source positioning characteristic quantity using the harmonic and interharmonic phasor data;

[0040] The sending module is used to send the low-frequency oscillation source positioning feature quantity and the broadband oscillation source positioning feature quantity to the master station for the master station to perform distributed positioning of the power grid oscillation source.

[0041] A distributed positioning device for a power grid oscillation source, applied to a master station, comprising:

[0042] The sending module is used to send the distributed positioning start command of the power grid oscillation source;

[0043] The receiving module is used to receive the oscillation source positioning characteristic value sent by the plant station;

[0044] The positioning module is used to perform distributed positioning of the power grid oscillation source based on the positioning characteristic quantity of the low-frequency oscillation source or the positioning characteristic quantity of the broadband oscillation source.

[0045] A distributed positioning system for a power grid oscillation source, comprising:

[0046] The power plant adopts the distributed positioning device for the power grid oscillation source to collect synchronized phasor data, harmonic and interharmonic phasor data, and oscillation power components, and starts the calculation of low-frequency oscillation source characteristic quantities and broadband oscillation source characteristic quantities according to the local oscillation monitoring alarm or the command issued by the master station;

[0047] The master station, the distributed power grid oscillation source positioning device is used to send a distributed power grid oscillation source positioning start command to the substation; receive and perform power grid low-frequency or wide-frequency oscillation source positioning based on the oscillation source characteristic quantities sent up by the substation.

[0048] An electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the power grid oscillation source distributed positioning method are implemented.

[0049] A computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the steps of the power grid oscillation source distributed positioning method are implemented.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] Aiming at the low-frequency and wide-frequency oscillation problems that may occur in the grid-connected operation of conventional power sources and distributed new energy sources under the background of the development of the power system, the present invention proposes a distributed oscillation source positioning method based on substations, power generation stations, and new energy stations. This method can monitor low-frequency and wide-frequency oscillations and calculate traceability characteristic quantities for all connected lines and equipment branches at the installation site of measurement or communication devices, and support the distributed positioning of power grid oscillation sources by sending the calculation results to the master station such as the dispatching center. The present invention can improve the real-time performance and comprehensiveness of power grid oscillation monitoring and positioning, and reduce the data storage, calculation, and processing pressure of the master station. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a schematic diagram of the architecture of the distributed oscillation source positioning system

[0053] Figure 2 It is a schematic diagram of the calculation process of the oscillation source distributed positioning characteristic quantity;

[0054] Figure 3 It is a block diagram of a distributed power grid oscillation source positioning system according to the present invention Figure 1 ;

[0055] Figure 4 It is a block diagram of a distributed power grid oscillation source positioning system according to the present invention Figure 2 ;

[0056] Figure 5 It is a schematic diagram of an electronic device according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0057] To enable those skilled in the art to better understand the solution of the present invention, the following will clearly and completely describe the technical solution in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0058] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned accompanying drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data used in appropriate cases can be interchanged so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0059] As Figure 1 shown, the first object of the present invention is to provide a method for distributed positioning of power grid oscillation sources, which is applied to the substation side and includes:

[0060] Collecting synchronous phasor, harmonic and inter-harmonic phasor data in units of busbars and branches in substations, power plants, new energy stations and other substations;

[0061] The substation device locally calculates the low-frequency oscillation source positioning characteristic quantity by using the synchronous phasor, and calculates the broadband oscillation source positioning characteristic quantity by using the harmonic and inter-harmonic phasor data;

[0062] The calculation and transmission of the oscillation source positioning characteristic quantity are triggered by the substation oscillation monitoring and warning or a command issued by the master station;

[0063] The substation uploads the low-frequency oscillation source positioning characteristic quantity and the broadband oscillation source positioning characteristic quantity to the master station such as the dispatching for wide-area oscillation source positioning of the power grid.

[0064] The present invention also provides a method for distributed positioning of power grid oscillation sources, which is applied to the master station side and includes:

[0065] The master station side issues a command for distributed positioning of power grid oscillation sources triggered by networking;

[0066] The master station side receives the oscillation source characteristic quantity uploaded by the substation, and the oscillation source characteristic quantity is calculated by the substation, and the method is:

[0067] Collect synchronous phasor, harmonic and inter-harmonic phasor data with busbars and branches as units;

[0068] Under the trigger of substation oscillation monitoring and alarming or master station issued commands, use the synchronous phasor to calculate the low-frequency oscillation source location characteristic quantity in-situ, and use the harmonic and inter-harmonic phasor data to calculate the wide-frequency oscillation source location characteristic quantity;

[0069] Perform distributed location of power grid oscillation sources according to the low-frequency oscillation source location characteristic quantity or the wide-frequency oscillation source location characteristic quantity.

[0070] Among them, the present invention proposes a method for distributed location of power grid oscillation sources, including low-frequency oscillation of 0.1 - 2.5 Hz and wide-frequency oscillation of frequencies above 2.5 Hz.

[0071] The principle of the present invention is based on synchronous phasors, harmonics, and inter-harmonic voltage and current phasors measured by devices such as wide-frequency measurement devices, synchronous phasor measurement devices, or measurement and control devices. Calculate the low-frequency oscillation source and wide-frequency oscillation source location characteristic quantities at the substation end respectively, and send the calculation results to the master station such as transmission dispatching to achieve distributed location of power grid oscillation sources.

[0072] The core of the present invention is to calculate the characteristic quantities for low-frequency and wide-frequency oscillation source location in-situ for synchronous phasor, harmonic and inter-harmonic phasor data at substations, power generation stations and new energy stations, and then send the calculation results to the master station such as dispatching to realize the analysis and location of power grid oscillation sources, thereby improving the real-time performance and comprehensiveness of power grid oscillation monitoring and location, and reducing the data processing pressure of the master station.

[0073] Such as Figure 1 and Figure 2 shown, the following specifically describes the specific steps for calculating the low-frequency oscillation source and wide-frequency oscillation source location characteristic quantities:

[0074] Taking the calculation of the low-frequency oscillation source location characteristic quantity as an example, it specifically includes:

[0075] Step 1: Monitor low-frequency oscillation in real time according to the alarm setting value P osc Monitor wide-frequency oscillation in real time according to the alarm setting value P sso When the peak-to-valley difference of the fundamental active power fluctuation exceeds P osc and reaches the set number of times X osc , trigger the low-frequency oscillation alarm signal;

[0076] Step 2: After the low-frequency oscillation alarm signal is triggered or the master station networking trigger signal is received, the measurement or communication device at the substation end calculates the transient energy integration based on the collected synchronous phasor data such as active power, reactive power, frequency and voltage. When the low-frequency oscillation alarm signal is eliminated or reaches the set integration duration T max_int , the device ends the transient energy flow integration calculation.

[0077] Step 3: The substation device performs linear fitting calculation on the transient energy integral curve and outputs the fitting slope k of the transient energy integral curve of branch j of bus i with the integral start time as the origin ij and the intercept b ij .

[0078] Step 4: The substation device writes the transient energy linear fitting parameter results into the communication protocol message with the master station. The master station locates the low-frequency oscillation source according to the grid topology and the fitting parameters k ij , b ij of the transient energy integral curves of each branch sent by the substation device

[0079] Step 5: When the amplitude of the oscillation power component of any frequency f k measured or monitored by the substation measurement or communication device exceeds P sso and reaches the set time T sso , a wide-frequency oscillation alarm signal is triggered

[0080] A general scheme for calculating characteristic quantities for low-frequency and wide-frequency oscillation source location based on synchronized phasor, harmonic, and interharmonic phasor data by measurement or communication devices at substations, power generation stations, and new energy stations, and uploading the characteristic quantities to the master station for oscillation source location

[0081] The starting methods and calculation periods for calculating characteristic quantities for low-frequency oscillation source location at substations are triggered by low-frequency oscillation alarm signals and master station networking trigger signals respectively. The calculation period is a settable parameter and ends when the low-frequency oscillation alarm is eliminated

[0082] Taking the calculation of characteristic quantities for wide-frequency oscillation source location as an example, it specifically includes

[0083] Step 6: After the wide-frequency oscillation alarm signal is triggered, the substation device selects the n oscillation power components with the largest amplitude (n is settable). Each calculation period tracks according to the set frequency deviation f offset . When the frequency f k of the oscillation power component and the oscillation frequency f lastk measured in the previous time satisfy Equation (1), it is determined as the same oscillation power component, and f lastk is set to f k for tracking in the next calculation period f k .

[0084] f lastk -f offset <f k <f lastk +f offset (1)

[0085] Step 7: According to the oscillation power frequency f kand fundamental frequency f base Match the harmonic or interharmonic phasors of the phase voltages and currents of phases A, B, and C. When the frequencies of the harmonic or interharmonic phasors satisfy Equation (2), the matched voltage and current phasors are denoted as U Xfk- 、I Xfk- ,U Xfk+ 、I Xfk+ ,Calculate the generated active power P Xfk_r according to Equation (3), and further calculate the oscillation frequency f k The total three-phase active power P fk_r generated on the branch.

[0086] f base -f k -f offset <f YX <f base -f k +f offset or f base +f k -f offset <f YX <f base +f k +f offset (2)

[0087]

[0088] P fk_r =P Afk_r +P Bfk_r +P Cfk_r (4)

[0089] Step 8: Calculate the cumulative energy over N periods that can be set When E Nfk ≤E set- ,Determine that this branch is the source of the oscillation power component P fk energy; when E Nfk ≥E set+ ,Determine that this branch consumes the energy of the frequency oscillation power component P fk . The absolute values of E set- 、E set+ can be the same or different.

[0090] Step 9: Mark the sign of the oscillation power with the frequency of f k at the i-th bus and j-th branch at the substation terminal. When E Nfk ≤E set- ,Mark it as negative; when E Nfk ≥E set+When it is positive, it is marked as positive; the measured oscillating power value after marking is sent to the master station; the master station locates the oscillation source according to the positive and negative signs and amplitudes of the oscillating power at each frequency of each branch.

[0091] Among them, the criterion for iterative tracking and identification of the broadband oscillating power component is that the oscillation frequency of the power component is within the deviation range of the frequency value recorded in the previous calculation period, and this deviation can be fixed or set.

[0092] The direction criterion of the broadband oscillating power component is determined by comparing the time integral of the active power of the associated voltage, current harmonics or inter-harmonics with the set value. If it is greater than the positive set value, it is determined to be positive; if it is less than the negative set value, it is determined to be negative.

[0093] The identification method of the broadband oscillating power component is to mark the positive and negative obtained from the direction determination of the broadband oscillating power component as the positive and negative signs of the amplitude of the broadband oscillating power component. The amplitude and frequency of the marked oscillating power component are transmitted to the master station through the communication protocol message.

[0094] Step 10: The master station according to each branch k sent by each power plant ij 、b ij , the positive and negative signs and amplitudes of the oscillating power component amplitudes respectively implement low-frequency oscillation source location and broadband oscillation source location.

[0095] The present invention is not limited by the structure, type of the measurement or communication device adopted in the implementation, the communication protocol between the power plant and the master station, and the best embodiment of the specific application.

[0096] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following further details the embodiments of the present invention with reference to the attached Figure 1 This further details the embodiments of the present invention. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but do not limit the present invention.

[0097] Step 1: The device at the power plant end calculates the fundamental active power P a 、I a 、U b 、I b 、U c 、I c based on the voltage and current synchronous phasors U base according to formula (5), and monitors the low-frequency oscillation in real time according to the alarm setting value P osc . When the difference between adjacent peaks and valleys of the active power P base exceeds P osc and reaches or exceeds the set number of times X osc , a low-frequency oscillation alarm signal is triggered.

[0098]

[0099] Step 2: After the low-frequency oscillation warning signal is triggered or the master station networking is triggered, based on the synchronized phasor data such as the measured active power, reactive power, frequency, and voltage, the branch transient energy integration calculation can be started according to Equation (6) or its simplified formula. When the low-frequency oscillation warning signal is eliminated or the set integration duration T max_int , the device ends the transient energy flow integration E dis calculation.

[0100] Or

[0101] Step 3: The substation device performs a linear fitting calculation on the curve of the transient energy integration E dis , and outputs the fitting slope k ij and intercept b ij of the transient energy integration curve of bus i, branch j with the integration start time as the origin. Write k ij , b ij into the GB / T26865.2 protocol message and send it to the master station.

[0102] Step 4: If the low-frequency oscillation warning signal is not eliminated, re-use the previous integration end time as T0, and execute (2) and (3) according to T max_int until the low-frequency oscillation warning signal is eliminated.

[0103] Step 5: The substation device calculates the instantaneous active power sampling sequence based on the voltage and current sampling values u a , i a , u b , i b , u c , i c according to Equation (7), extracts the leading 10 oscillation power components through the FFT algorithm, and the amplitude P fk and frequency f k of the oscillation power components, where k = 1 to 10. Monitor the broadband oscillation power components one by one according to the warning threshold P sso . If the amplitude of the oscillation power component of any frequency f k exceeds P sso for the set time T sso , trigger the broadband oscillation warning signal.

[0104] {P f1 ...P fn} = FFT{u a i a + u b i b + u c i c} (7)

[0105] (6) After the wide - frequency oscillation alarm signal is triggered, the substation device selects the 5 oscillation power components with the largest amplitude; in each calculation period, track each oscillation power component according to the set frequency deviation f offset = 2.5Hz. When the oscillation power frequency f k is within the deviation from the previously measured oscillation frequency f lastk satisfying Equation (1), it is judged as the same oscillation power component, and set f lastk to f k for the tracking of the next calculation period f k .

[0106] (7) According to f k , match the relevant phase - voltage, current harmonics and inter - harmonics phasors of phases A, B, and C. Match the voltage and current phasors according to the frequency deviation conditions shown in Equation (2), and denote them as U Xfk- , I Xfk- , U Xfk+ , I Xfk+ respectively. Calculate the single - phase active power P Xfk_r generated by them and the active powers P fk_r of phases A, B, and C according to Equations (3) and (4) respectively.

[0107] (8) Take N = 10 and calculate the cumulative energy E Nfk . When E Nfk ≤E set- , determine that this branch is the source of the oscillation energy with frequency P fk ; when E Nfk ≥E set+ , determine that this branch consumes the oscillation energy with frequency f k . The absolute values of E set- and E set+ can be the same or different.

[0108] (9) The substation acquisition and measurement device marks the sign of the oscillation power component P fk of branch j of bus i. When E Nfk ≤E set- , mark it as negative; when E Nfk ≥E set+ , mark it as positive; write the measured value of the marked oscillation power component into the GB / T26865.2 protocol message and send it to the master station;

[0109] (10) The master station realizes low - frequency oscillation source localization and wide - frequency oscillation source localization respectively according to the oscillation power component P ij , b ij , amplitude and positive / negative sign of each branch k fk sent by each substation.

[0110] Such as Figure 3As shown in the figure, the present invention also provides a distributed positioning device for power grid oscillation sources, which is applied to a substation and includes:

[0111] An acquisition module, integrated in the substation device, for acquiring synchronous phasor data, harmonic and inter-harmonic phasor data;

[0112] A calculation module, integrated in the substation device, for calculating low-frequency oscillation source positioning characteristic quantities based on synchronous phasor data, and calculating broadband oscillation source positioning characteristic quantities based on harmonic and inter-harmonic phasor data and broadband oscillation power components;

[0113] An upload module, integrated in the substation device, for uploading low-frequency oscillation source positioning characteristic quantities and broadband oscillation source positioning characteristic quantities, and used for the main station such as dispatching to perform power grid low-frequency and broadband oscillation source positioning.

[0114] In the calculation module, the calculation of the low-frequency oscillation source positioning characteristic quantity by using synchronous phasor data specifically includes:

[0115] The criterion for the substation to trigger a low-frequency oscillation alarm is: within the set number of oscillations X osc the average peak-to-valley difference of the fundamental active power P base fluctuation exceeds the alarm threshold P osc ;

[0116] After the substation device triggers a low-frequency oscillation alarm or receives a main station command, it uses the collected synchronous phasor data to start transient energy integral calculation with buses and branches as units; when the low-frequency oscillation alarm is eliminated or the set integration duration T max_int is reached, the device ends the transient energy flow integral calculation;

[0117] The substation device performs transient energy integral curve fitting calculation with buses and branches as units and the integral start time as the origin, and outputs the low-frequency oscillation characteristic quantities of each bus i and branch j. The low-frequency oscillation characteristic quantity is the fitting slope k ij and intercept b ij .

[0118] The calculation method of the fundamental active power P base is:

[0119]

[0120] In formula (1), U a , I a , U b , I b , U c , I c are voltage and current synchronous phasors;

[0121] The substation device uses synchronous phasor data to calculate the transient energy integral of each bus i and branch j. The specific method is:

[0122] or

[0123] In formula (2), T max_int is the set integration duration, and E dis is the transient energy integration.

[0124] In the calculation module, calculating the wide - frequency oscillation source localization feature quantity by using the harmonic and inter - harmonic phasor data specifically includes:

[0125] The substation device calculates the instantaneous active power sampling sequence based on the voltage and current sampling values u a , i a , u b , i b , u c , i c , extracts the dominant oscillation power component through the FFT algorithm according to formula (3), and the amplitude P fk and frequency f k of the oscillation power component;

[0126] {P f1 ...P fn} = FFT{u a i a + u b i b + u c i c} (3)

[0127] The substation device takes the bus branch as a unit. Within the set time T sso , when the substation device monitors that the amplitude of any wide - frequency oscillation power component P fk continuously exceeds the set alarm threshold P sso , a wide - frequency oscillation alarm is triggered.

[0128] After the wide - frequency oscillation alarm is triggered, the substation device tracks the n oscillation power components with the largest amplitudes at the set frequency deviation f offset in each calculation cycle. When the deviation between the frequency f k of the oscillation power component and the previously measured oscillation frequency f lastk satisfies formula (4), it is determined as the same oscillation power component, and f lastk is updated to f k , and the tracking of f k in the next cycle is executed;

[0129] f lastk - f offset < f k < f lastk + f offset (4)

[0130] Further, according to the oscillation power component P fk at the frequency f k and the fundamental frequency f base , match the harmonic or interharmonic phasors of the phase voltage and current, as shown in Equation (5); obtain the voltage and current phasors: U Xfk- , I Xfk- , U Xfk+ , I Xfk+ ; the subscript k represents the phase A, B, C;

[0131] f base -f k -f offset <f YX <f base -f k +f offset or f base +f k -f offset <f YX <f base +f k +f offset (5).

[0132] The power generation plant device calculates the generated active power P Xfk_r according to Equation (6), and calculates the broadband oscillation power component P fk of the total active power P fk_r generated on the branch;

[0133]

[0134] P fk_r =P Afk_r +P Bfk_r +P Cfk_r (7)

[0135] Calculate the cumulative energy according to the set number of cycles N When E Nfk ≤E set- , mark the amplitude of the oscillation power component P fk of the bus i branch j as negative, and when E Nfk ≥E set+ , mark the amplitude of the oscillation power component P fk as positive;

[0136] Transmit the marked oscillation power amplitude to the master station: a characteristic quantity for wideband oscillation source localization.

[0137] Among them, the distributed positioning of the power grid oscillation source means that the substation device calculates the amplitude and positive / negative sign of each branch and each oscillation power component, and the master station locates the oscillation source in the network based on the broadband oscillation source positioning characteristic quantities sent by the substations.

[0138] As Figure 4 shown, the present invention also provides a distributed positioning device for power grid oscillation sources, including:

[0139] A sending module, integrated in the master station such as the power grid dispatching, for sending the start command for the distributed positioning of the power grid oscillation source;

[0140] A receiving module, integrated in the master station such as the power grid dispatching, for receiving the oscillation source positioning characteristic quantities sent by the substations;

[0141] A positioning module, integrated in the master station such as the power grid dispatching, for performing distributed positioning of the power grid oscillation source according to the low-frequency oscillation source positioning characteristic quantities or broadband oscillation source positioning characteristic quantities.

[0142] The distributed positioning of the power grid oscillation source according to the low-frequency oscillation source positioning characteristic quantities or broadband oscillation source positioning characteristic quantities specifically includes:

[0143] The master station sends the distributed positioning command of the power grid oscillation source triggered by network connection;

[0144] The master station receives the oscillation source characteristic quantities sent by the substations, and the oscillation source characteristic quantities are calculated by the substations. The method is as follows:

[0145] Collect synchronous phasor, harmonic and inter-harmonic phasor data with busbars and branches as units;

[0146] Under the trigger of substation oscillation monitoring and alarm or the command sent by the master station, use the synchronous phasor to calculate the low-frequency oscillation source positioning characteristic quantities locally, and use the harmonic and inter-harmonic phasor data to calculate the broadband oscillation source positioning characteristic quantities;

[0147] Perform distributed positioning of the power grid oscillation source according to the low-frequency oscillation source positioning characteristic quantities or broadband oscillation source positioning characteristic quantities.

[0148] Specifically, the calculation method of calculating the low-frequency oscillation source positioning characteristic quantities using the synchronous phasor locally and calculating the broadband oscillation source positioning characteristic quantities using the harmonic and inter-harmonic phasor data is as described in the above embodiments and will not be repeated here.

[0149] As Figure 1 shown, the present invention also provides a distributed positioning system for power grid oscillation sources, including:

[0150] A substation adopts a distributed positioning device for grid oscillation sources applied to the substation side, which is used to collect synchronous phasor data, harmonic and inter-harmonic phasor data, and oscillation power components, and starts calculating the characteristic quantities of low-frequency oscillation sources and wide-frequency oscillation sources according to local oscillation monitoring alarms or commands issued by the master station.

[0151] The master station adopts a distributed positioning device for grid oscillation sources applied to the master station side, which is used to send a start command for the distributed positioning of grid oscillation sources to the substation; receives and locates the low-frequency or wide-frequency oscillation sources of the power grid according to the characteristic quantities of the oscillation sources sent by the substation.

[0152] As Figure 5 shown, the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method for distributed positioning of grid oscillation sources are implemented.

[0153] The steps of the method for distributed positioning of grid oscillation sources adopt the above positioning method.

[0154] The present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the method for distributed positioning of grid oscillation sources are implemented.

[0155] The steps of the method for distributed positioning of grid oscillation sources adopt the above positioning method.

[0156] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can be implemented in the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can be implemented in the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0157] The present invention is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows 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 the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the specified functions in one Figure 1 one or more flows and / or multiple flows and / or blocks Figure 1 one or more blocks or multiple blocks.

[0158] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-readable memory produce a manufacture including an instruction device that implements the functions specified in one or more of the processes and / or blocks Figure 1 in one or more of the processes and / or blocks Figure 1 in the block or blocks.

[0159] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in one or more of the processes and / or blocks Figure 1 in one or more of the processes and / or blocks Figure 1 in the block or blocks.

[0160] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the specific embodiments of the present invention. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A distributed positioning method for power grid oscillation sources, applied to the substation side, is characterized in that Including: Collecting synchronous phasor, harmonic and inter - harmonic phasor data in units of busbars and branches; Under the trigger of substation oscillation monitoring and alarming or master - station issued commands, calculating low - frequency oscillation source location characteristic quantities locally using synchronous phasors, and calculating broadband oscillation source location characteristic quantities using harmonic and inter - harmonic phasor data; Sending the low - frequency oscillation source location characteristic quantities and broadband oscillation source location characteristic quantities to the master - station for the master - station to perform distributed location of power grid oscillation sources; The calculating of the low - frequency oscillation source location characteristic quantities using synchronous phasor data specifically includes: The criterion for the substation to trigger the low-frequency oscillation alarm is that within the set number of oscillations , the average peak-to-valley difference of the fundamental active power fluctuations exceeds the alarm threshold ; After the substation device triggers the low-frequency oscillation alarm or receives the master station command, it uses the collected synchronized phasor data to start the transient energy integration calculation with the bus and branch as units; when the low-frequency oscillation alarm is eliminated or the set integration duration is reached , the device ends the transient energy flow integration calculation; The substation device takes the bus branch as a unit and performs transient energy integral curve fitting calculation with the integral start time as the origin, and outputs the low-frequency oscillation characteristic quantities of each bus branch . The low-frequency oscillation characteristic quantities are the fitting slope and intercept .

2. The distributed location method of power grid oscillation sources according to claim 1, characterized in that, The fundamental active power The calculation method is as follows: （1） In formula (1), , , , , , are voltage and current synchronous phasors; The substation device uses synchronized phasor data to calculate the transient energy integrals of each busbar branch , and the specific method is as follows: （2） In formula (2), is the set integration duration, is the transient energy integration.

3. The distributed location method of power grid oscillation sources according to claim 1, characterized in that, After the substation device triggers a low-frequency oscillation alarm or receives a master station command, if the low-frequency oscillation alarm has not been eliminated and the transient energy integration duration is reached , the slope and intercept are obtained by fitting. At the current moment , the transient energy integration and fitting are cyclically executed again according to the integration duration until the low-frequency oscillation alarm is eliminated.

4. The distributed location method of power grid oscillation sources according to claim 1, characterized in that, The distributed location of the power grid oscillation source refers to the location of the low-frequency oscillation source based on the power grid topology and the fitting parameters of the transient energy integral curves of each branch sent from the substation terminal , .

5. The distributed location method of power grid oscillation sources according to claim 1, characterized in that, The calculating of the broadband oscillation source location characteristic quantities using harmonic and inter - harmonic phasor data specifically includes: The substation device is based on voltage and current sampling values , , , , , Calculate the instantaneous active power sampling sequence, and extract the dominant oscillating power component through the FFT algorithm according to Equation (3). The amplitude and frequency ; （3） The substation device takes the bus branch as a unit and within a set time During this period, the substation device monitors that any broadband oscillation power component has an amplitude continuously exceeding the set alarm threshold , triggering a broadband oscillation alarm.

6. The distributed location method of power grid oscillation sources according to claim 5, characterized in that, After the wide - frequency oscillation alarm is triggered, the substation device calculates the set frequency deviation in each calculation cycle to track the oscillation power component with the largest amplitude among them. When the frequency of the oscillation power component deviates from the oscillation frequency measured last time and satisfies Equation (4), it is judged as the same oscillation power component, and is updated to , and the tracking in the next cycle is executed. （4） Further by the oscillating power component frequency and fundamental frequency , match the harmonic or interharmonic phasors of the phase voltage and current, as shown in Equation (5); obtain the voltage and current phasors by matching: 、 , 、 ; the subscript k represents the phase A, B, C; or (5).

7. The distributed location method of power grid oscillation sources according to claim 5, characterized in that, The active power generated by the substation device calculated according to Equation (6) , calculate the broadband oscillation power component according to Equation (7) The total active power generated on the branch ; （6） （7） According to the set number of cycles Calculate the cumulative energy When the busbar branch the amplitude of the oscillating power component is marked as negative. When the oscillating power component the amplitude is marked as positive; Transmitting the marked oscillation power amplitude to the master - station: the characteristic quantity of broadband oscillation source location.

8. The distributed location method of power grid oscillation sources according to claim 5, characterized in that, The performing of distributed location of power grid oscillation sources means that the substation device calculates the amplitude and positive / negative sign of each branch and each oscillation power component, and the master - station locates the oscillation sources in the network according to the broadband oscillation source location characteristic quantities sent by the sub - stations.

9. A distributed positioning device for power grid oscillation sources, which is applied to the substation side, is characterized in that Including: A collecting module for collecting synchronous phasor, harmonic and inter - harmonic phasor data in units of busbars and branches; A calculating module for calculating low - frequency oscillation source location characteristic quantities locally using synchronous phasors and calculating broadband oscillation source location characteristic quantities using harmonic and inter - harmonic phasor data under the trigger of substation oscillation monitoring and alarming or master - station issued commands; An uploading module for sending the low - frequency oscillation source location characteristic quantities and broadband oscillation source location characteristic quantities to the master - station for the master - station to perform distributed location of power grid oscillation sources; In the calculating module, the calculating of the low - frequency oscillation source location characteristic quantities using synchronous phasor data specifically includes: The criterion for the substation to trigger the low-frequency oscillation alarm is that within the set number of oscillations the average peak-to-valley difference of the fundamental active power fluctuations exceeds the alarm threshold ; After the substation device triggers the low-frequency oscillation alarm or receives the master station command, it uses the collected synchronized phasor data to start the transient energy integration calculation with the bus and branch as units; when the low-frequency oscillation alarm is eliminated or the set integration duration is reached , the device ends the transient energy flow integration calculation; The substation device takes the bus branch as a unit, performs transient energy integral curve fitting calculation with the integral start time as the origin, and outputs the low-frequency oscillation characteristic quantities of each bus branch . The low-frequency oscillation characteristic quantity is the fitting slope and intercept .

10. The distributed location device of power grid oscillation sources according to claim 9, characterized in that, The fundamental active power The calculation method is as follows: （1） In Equation (1), , , , , , are voltage and current synchronous phasors; The substation device uses synchronous phasor data to calculate the transient energy integrals of each busbar branch , and the specific method is as follows: （2） In formula (2), is the set integration duration, is the transient energy integration.

11. The distributed location device of power grid oscillation sources according to claim 9, characterized in that, In the calculating module, the calculating of the broadband oscillation source location characteristic quantities using harmonic and inter - harmonic phasor data specifically includes: The substation device is based on voltage and current sampling values , , , , , Calculate the instantaneous active power sampling sequence, and extract the dominant oscillating power component through the FFT algorithm according to Equation (3). The amplitude and frequency ; （3） The substation device takes the bus branch as a unit and within the set time During this period, the substation device monitors any broadband oscillation power component whose amplitude continuously exceeds the set alarm threshold value , triggering a broadband oscillation alarm.

12. The distributed location device of power grid oscillation sources according to claim 11, characterized in that, After the wide-frequency oscillation alarm is triggered, the plant station device tracks the oscillation power component with the largest amplitude at the set frequency deviation in each calculation period. When the frequency of the oscillation power component meets the deviation in Equation (4) from the oscillation frequency measured last time, it is determined to be the same oscillation power component, and is updated to , and the tracking of the next cycle is executed. ​ （4） Further by the oscillation power component frequency and the fundamental frequency , match the harmonic or interharmonic phasors of the phase voltage and current, as shown in Equation (5); obtain the voltage and current phasors by matching: 、 , 、 ; the subscript k represents the phase types A, B, and C; or (5).

13. The distributed location device of power grid oscillation sources according to claim 11, characterized in that, The active power generated by the substation device calculated according to Equation (6) , calculate the broadband oscillation power component according to Equation (7) The total active power generated on the branch ; （6） （7） According to the set number of cycles Calculate the cumulative energy When the oscillation power component of the busbar branch is marked negative in magnitude, and when the oscillation power component is marked positive in magnitude; ​ Transmitting the marked oscillation power amplitude to the master - station: the characteristic quantity of broadband oscillation source location.

14. The distributed location device of power grid oscillation sources according to claim 11, characterized in that, The distributed positioning of the power grid oscillation source refers to the plant station device calculating the amplitudes and positive / negative signs of each branch and each oscillation power component, and the master station positioning the oscillation source in the network based on the broadband oscillation source positioning characteristic quantities sent by the slave stations.

15. A distributed positioning device for power grid oscillation sources, which is applied to the master station side and is based on the distributed positioning method for power grid oscillation sources according to any one of claims 1 to 8, characterized in that, It includes: A sending module, used to send the start command for the distributed positioning of the power grid oscillation source; A receiving module, used to receive the oscillation source positioning characteristic quantities sent by the plant station; A positioning module, used to perform distributed positioning of the power grid oscillation source according to the low-frequency oscillation source positioning characteristic quantities or broadband oscillation source positioning characteristic quantities.

16. A distributed positioning system for power grid oscillation sources, characterized in that, It includes: A plant station, adopting the power grid oscillation source distributed positioning device described in any one of claims 9 to 15, used to collect synchronous phasor data, harmonic and inter-harmonic phasor data, and oscillation power components, and start the calculation of low-frequency oscillation source characteristic quantities and broadband oscillation source characteristic quantities according to local oscillation monitoring and alarm or commands sent by the master station; A master station, adopting the power grid oscillation source distributed positioning device described in claim 15, used to send the start command for the distributed positioning of the power grid oscillation source to the plant station; receive and position the low-frequency or broadband oscillation source of the power grid according to the oscillation source characteristic quantities sent by the plant station.

17. An electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, where when the processor executes the computer program, the steps of the power grid oscillation source distributed positioning method described in any one of claims 1-8 are implemented.

18. A computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the power grid oscillation source distributed positioning method described in any one of claims 1-8 are implemented.

Images