CN115632410A - Broadband oscillation protection method for new energy power system - Google Patents

Broadband oscillation protection method for new energy power system Download PDF

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Publication number
CN115632410A
CN115632410A CN202211296164.4A CN202211296164A CN115632410A CN 115632410 A CN115632410 A CN 115632410A CN 202211296164 A CN202211296164 A CN 202211296164A CN 115632410 A CN115632410 A CN 115632410A
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oscillation
new energy
frequency
station
admittance
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Inventor
张淼
刘树
常富杰
操丰梅
时伯年
孙刚
王莹莹
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Beijing Sifang Automation Co Ltd
Beijing Sifang Engineering Co Ltd
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Beijing Sifang Automation Co Ltd
Beijing Sifang Engineering Co Ltd
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
    • H02J3/241—The oscillation concerning frequency
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
    • H02H7/261—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations
    • H02H7/262—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations involving transmissions of switching or blocking orders
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
    • H02J13/00002—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by monitoring
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/381—Dispersed generators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
    • H02J2203/20—Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]

Abstract

A method for broadband oscillation protection of a new energy power system uses a new energy station to send out a three-phase voltage/current real-time measured value of a line. Firstly, evaluating the system stability by a proposed real-time frequency detection method; secondly, when the system has continuous broadband oscillation, the oscillation source is positioned, the output of each line to the oscillation is sequenced according to the calculation result of the proposed method, and then the station which should be cut off preferentially is found. The method is characterized in that: monitoring and protecting in real time by utilizing sampling information in a rolling time window; realizing an algorithm based on a characteristic system, and taking a frequency measurement value as a stability criterion; when oscillation occurs, the modal admittance of the oscillation frequency is analyzed on the dq coordinate axis, so that the magnitude of the output of each line to the oscillation is quantitatively represented.

Description

Broadband oscillation protection method for new energy power system
Technical Field
The invention belongs to the technical field of novel power system monitoring and protection, and particularly relates to a broadband oscillation stability evaluation based on a characteristic implementation algorithm and a novel power system broadband oscillation traceability and new energy wind field selection and cutting sequencing algorithm based on analysis admittance on a dq rotation coordinate system.
Background
With large-scale new energy grid connection, high-voltage direct-current power transmission network formation and power electronic load operation, modern power systems face more and more broadband oscillation problems. Over the last decade, many broadband oscillation cases have occurred worldwide. The broadband oscillation may damage power equipment, cause the new energy generator set to stop running and the like, seriously affect the equipment safety and threaten the stable running of the system, and become one of the risks seriously threatening the stable running of the system in a high-proportion new energy system. The structure of power electronic equipment in a novel power system is complex and has nonlinearity and time-varying property. After broadband oscillation occurs, common research means such as establishing an analysis model and establishing a simulation platform to analyze the broadband oscillation problem need to analyze and analyze after the oscillation occurs, and the real-time performance is not provided. In the first time of oscillation, effective monitoring and control are required to be achieved, so that the oscillation is effectively controlled as soon as possible at the minimum cost, and the reliable operation of a power system is ensured.
It is expected that broadband oscillation monitoring and control research will become a major concern in the development of new energy systems in the future. The current Wide Area Monitoring System (WAMS) is based on synchronous vector monitoring (PMU) as monitoring data, and can realize dynamic real-time online monitoring, analysis and control of a large-span power system. However, the existing PMU (phasemeter unit) and WAMS (wide-area meter system) are difficult to satisfy the centralized monitoring and protection functions of wide-frequency range and multi-mode oscillation for the new energy collection system. The following points need to be improved:
the existing monitoring device cannot cover the monitoring protection of high-frequency oscillation from about 0.1Hz low frequency to over 1000 Hz;
the reliability of the stability judgment of the novel power system is not high;
when the problem of broadband oscillation commonly influenced by a plurality of new energy stations is found, oscillation sources cannot be reasonably sequenced, so that part of stations are effectively cut off to inhibit oscillation.
Based on the above consideration, regional power grid operation control personnel urgently need a broadband oscillation monitoring and protecting mechanism suitable for a high-proportion new energy collection system to maintain reliable and stable operation of the new energy system.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention provides a broadband oscillation protection method for a new energy power system. The method comprises the steps of collecting three-phase voltage and current of a line sending end of a new energy station in real time, synchronously calculating positive sequence frequency of the three-phase voltage, converting the voltage/current from an abc static coordinate system to a dq rotating coordinate system by using the frequency, calculating oscillation frequency and damping ratio if oscillation judgment conditions are met, judging whether the new energy station is an oscillation source or not through admittance of the new energy station sending end under the oscillation frequency, sequencing the admittance, finding out the most serious new energy station and cutting off the new energy station. The method can avoid analyzing two frequency components caused by coupling of one oscillation mode, and gives consideration to the complexity and effectiveness of priority sequencing when the new energy is switched.
The invention adopts the following technical scheme.
A broadband oscillation protection method for a new energy power system is characterized by comprising the following steps:
step 1, acquiring three-phase voltage and current of a line output end of any required new energy station in real time through a measuring device;
step 2, synchronously calculating the positive sequence frequency of the three-phase voltage through the DDSRF-PLL, and obtaining the voltage and the current on the dq rotation coordinate system;
and 3, in the real-time rolling window, judging the stability of the positive sequence frequency in the time period: if the oscillation judging condition is not met, returning to the step 2 to continue monitoring; if the oscillation judgment condition is met, calculating the oscillation frequency and the damping ratio, and continuing to analyze in the step 4;
step 4, calculating the admittance of the corresponding oscillation mode on the upper side through the voltage and the current on the dq axis;
and 5, judging whether the station is an oscillation source or not through the admittance of the sending end of each new energy station under the oscillation frequency, sequencing the admittance, finding out the most serious new energy station and cutting off the station.
Preferably, in step 3, the stability is determined to be at a total duration T 0 Within a time window of, with T s For sampling frequency, the positive sequence frequency omega in the real-time window + Carrying out stability judgment;
the stability determination method combines two factors, firstly determines the frequency omega in the time window + Whether the difference of the local extreme values exceeds the warning value +/-Delta f lim (Hz) and the number of occurrences exceeds N p (ii) a If the conditions are met, starting a feature system implementation algorithm to calculate the positive sequence frequency omega + Of (d) is the oscillation mode frequency (f) 1 ,f 2 ,…,f N ) And damping ratio (D) 1 ,D 2 ,…,D N ) N is the number of the monitored oscillation modes; judging the stability according to the damping ratio of the oscillation mode;
at any f n Under the corresponding mode n, if the damping ratio meets 0 percent<D n <D lim If the system is in the critical stability and has oscillation risk, giving out early warning to continue monitoring without cutting off the new energy station; if the damping ratio of the oscillation mode satisfies D n If the frequency is less than or equal to 0%, the system generates broadband oscillation, gives out early warning and prepares for next-step new energy station cutting.
Preferably, in step 4, the voltage and current calculation on the dq axis corresponds to the oscillation mode onAdmittance, calculating the corresponding oscillation mode f on the dq axis n Voltage/current vector of lower, i.e. V d (f n )，V q (f n ),I d (f n ) And I q (f n ) And calculating the admittance matrix on the dq axis according to the following formula:
Figure BDA0003902698000000031
wherein M =1,2,3, \ 8230, M is the total number of the measured new energy stations; n =1,2,3, \ 8230, N is the number of oscillation modes detected.
Preferably, in step 5, the admittance ordering refers to the qq-axis admittance components
Figure BDA0003902698000000032
When the temperature is higher than the set temperature
Figure BDA0003902698000000033
When negative, the new energy station is the source of the broadband oscillation, if
Figure BDA0003902698000000034
It means that the new energy station m has a greater contribution to the oscillation phenomenon than the other station k, and m should be preferentially removed.
The invention has the advantages that compared with the prior art,
1) The invention provides a method for protecting broadband oscillation of a power system, which is characterized in that the positive sequence frequency omega is calculated in real time through DDSRF-PLL + Excludes negative sequence frequency omega - The second harmonic is generated by the coupling action; and the analyzed voltage and current on the dq axis are not interfered by harmonic waves, and the calculated admittance vector is more accurate. In addition, compared with the common method of carrying out stability judgment by active power, the method utilizes the positive sequence frequency omega + The stability judgment is more accurate. In practical engineering, it has been found that when the system has obvious oscillation, the active power does not have obvious oscillation, and the positive sequence frequency can reflect the dynamic characteristic of the node voltage phase angle in the oscillation process.
2) The invention judges the magnitude of the output force to the oscillation phenomenon by calculating the admittance of the transmitting end of each station on the dq axis. Compared with the analytic method on the traditional abc three-phase coordinate system, the method provided by the invention can avoid analyzing two frequency components caused by coupling of one oscillation mode. The reason for this is that in the dq rotation coordinate system, only a component at one frequency exists for one oscillation mode. In addition, only Y is utilized qq (f n ) The sequencing is performed because the negative impedance characteristic of the new energy station is mainly reflected on the qq component. The complexity and the effectiveness of the priority sequencing during the new energy cutting are considered.
Drawings
FIG. 1 is a flow chart of a method for broadband oscillation protection of an electrical power system according to the present invention;
FIG. 2 is a diagram of a dual synchronous decoupling phase-locked loop;
FIG. 3 is a schematic diagram of a positive and negative sequence frequency decoupling module of a double synchronous decoupling phase-locked loop;
fig. 4 is a schematic diagram of a new energy grid-connected system composed of two new energy stations according to an embodiment of the present invention;
fig. 5 is a simulation diagram of three-phase abc voltages/currents at the output ends of two new energy terminals in the embodiment of the invention;
fig. 6 is a schematic frequency diagram of the synchronous calculation of the new energy station 1 according to the embodiment of the present invention;
fig. 7 is a schematic diagram of dq-axis voltage/current synchronously calculated by the new energy station 1 according to the embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. The embodiments described herein are only some embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art without inventive step, are within the scope of protection of the present invention.
A method for protecting broadband oscillation of an electric power system, as shown in fig. 1, includes the following steps:
step 1, acquiring three-phase voltage and current of a line output end of any required new energy station in real time through a measuring device;
for example, in the new energy system shown in fig. 4, three-phase voltage/current data of two new energy stations 1 and 2 on the 220kV side are measured. Three-phase voltage/current data of two new energy station lines are shown in fig. 5, the time length of the data is 2 seconds, and the sampling interval is 500 microseconds (the sampling frequency is 2000 Hz).
Step 2, synchronously calculating the positive sequence frequency of the three-phase voltage through the DDSRF-PLL, and obtaining the voltage and the current on the dq rotation coordinate system;
synchronously calculating the positive sequence frequency of the three-phase voltage, and converting the voltage/current from an abc static coordinate system to a dq rotating coordinate system by using the frequency; the positive sequence frequency omega of the port voltage is calculated in real time through DDSRF-PLL (Double Synchronous decoupling Phase-locked Loop) + And phase angle theta + . And simultaneously pass through omega + And theta + Will V abc And I abc Conversion to positive-sequence rotating coordinate system
Figure BDA0003902698000000041
And
Figure BDA0003902698000000051
for the measured three-phase voltage, the positive and negative sequence components obtained first at the power frequency can be expressed as:
Figure BDA0003902698000000052
wherein +1 represents a positive sequence power frequency component and-1 represents a negative sequence power frequency component. The voltage is at dq +1 And dq -1 The coordinate axes may be respectively expressed as follows:
Figure BDA0003902698000000053
Figure BDA0003902698000000054
the above set of equations demonstrates that at dq +1 The alternating term in (1) is derived from dq -1 The coupling action produces a harmonic component at a frequency of 2 omega. To decouple this mutual coupling, the DDSRF-PLL structure shown in fig. 2 is used in the present invention to measure the frequency.
The DDSRF-PLL structure comprises an alpha beta-dq conversion module:
Figure BDA0003902698000000055
the DDSRF-PLL structure comprises a decoupling module as shown in fig. 3, where n, m are +1, -1, respectively.
The DDSRF-PLL structure contains a low-pass filter:
Figure BDA0003902698000000056
the low pass filter parameters may be adjusted according to the wide frequency range of interest in a particular practical system. If the problem of oscillation in the high frequency range needs to be monitored, it can be omitted.
Calculated after decoupling
Figure BDA0003902698000000057
Calculating frequency omega 'and phase angle theta' by SRF-PLL + ＝ω',θ + (= θ'), negative sequence ω) - ＝-ω',θ - And (d) = -theta'. By the same token to obtain
Figure BDA0003902698000000058
As shown in fig. 6, the frequencies of the 5 th to 7 th seconds (total 2 seconds) are acquired by the above-described DDSRF-PLL method.
And step 3: and in a real-time rolling window, performing stability judgment on the positive sequence frequency in the time period: if the oscillation judging condition is not met, returning to the step 2 to continue monitoring; if the oscillation judgment condition is met, calculating the oscillation frequency and the damping ratio, and continuing to analyze in the step 4;
the stability is judged when the total duration is T 0 In a time window of =2s, in T s =500 μ s as sampling frequency, for positive sequence frequency ω within a real time window + And (6) judging the stability.
The stability determination method combines two factors, firstly determines the frequency omega in the time window + Whether the difference of the local extreme values exceeds the warning value +/-Delta f lim =1 (Hz), and the number of occurrences exceeds N p =2; starting an ERA (eigen-system implementation) Algorithm to calculate the positive sequence frequency omega due to the condition that the positive sequence frequency local extreme value continuously appears to exceed 1.7Hz + Of (d) is the oscillation mode frequency (f) 1 ,f 2 ,…,f N ) And damping ratio (D) 1 ,D 2 ,…,D N ) And N is the number of the monitored oscillation modes. And judging the stability according to the damping ratio of the oscillation mode.
The ERA can calculate a Linear time-invariant (LTI) discrete system from the measured frequencies in the 2-second time window:
x k+1 ＝Ax k +Bu k ，y k ＝Cx k +Du k
since the input assumed by ERA is a pulse signal, an i/o model cannot be estimated, but rather a frequency domain equation of state defined by the a, B, C, D matrices is estimated from the measured output signal. The order of which needs to be defined in advance. The measurement signal in the frequency domain can be expressed as:
Figure BDA0003902698000000061
where A' is the system matrix of the continuous dynamic equation, V is its right eigenvector, and Ω is its diagonal matrix.
For the k-th measurement signal, it can be expressed in the frequency domain
Figure BDA0003902698000000062
The key step in ERA is the construction of two Hankel matrices:
Figure BDA0003902698000000071
Figure BDA0003902698000000072
the Hankel matrix can be decomposed into:
Figure BDA0003902698000000073
wherein
Figure BDA0003902698000000074
Is an observability (observability) matrix,
Figure BDA0003902698000000075
is a controllability matrix. ERA is obtained by Singular Value Decomposition (SVD) and order reduction
Figure BDA0003902698000000076
And
Figure BDA0003902698000000077
and the A matrix can pass through H 1 And H 2 And finding.
Further, eigenvalue decomposition in the A matrix obtains the oscillation mode frequency (f) 1 ，f 2 ，...，f N ) And damping ratio (D) 1 ，D 2 ，...，D N ) And N is the number of the monitored oscillation modes. And judging the stability according to the damping ratio of the oscillation mode.
At any f n Under the corresponding mode n, if the damping ratio meets 0 percent<D n <D lim If the system is in critical stability and has oscillation risk, giving out early warning to keep cutting off the new energy station and continuing monitoring; if the damping ratio of the oscillation mode satisfies D n If the frequency is less than or equal to 0%, the system generates broadband oscillation, gives out early warning and prepares for next-step new energy station cutting.
In this case, a primary oscillation mode is detected, the frequency of which is f 1 =6.28Hz, the corresponding damping ratio is D 1 And (5) the content of the product is = -0.39%. And (4) showing that the system has the broadband oscillation problem, giving out an early warning and continuing the following steps to judge the new energy station which is cut off most preferentially.
Step 4, calculating the admittance of the corresponding oscillation mode on the upper portion through the voltage and the current on the dq axis;
at this time, the judgment result shows that oscillation exists, and the step 2 is passed, and the voltage/current with the time length of 2 seconds and the sampling interval of 500 microseconds is obtained
Figure BDA0003902698000000081
Then, the corresponding oscillation mode f is calculated by FFT 1 Vector at =6.28Hz, i.e. V d (f 1 ) And V q (f 1 ) Similarly, calculate the current vector I d (f 1 ) And I q (f 1 ) And calculating the admittance matrix on the dq axis according to the following formula:
Figure BDA0003902698000000082
wherein, m =1,2 respectively represents 2 new energy stations required in the system of the embodiment.
And 5, judging whether the new energy station is an oscillation source or not through the admittance of the sending end of each new energy station under the oscillation frequency, sequencing the admittances, and finding out and cutting off the most serious new energy station.
When broadband oscillations occur in new energy systems, they are usually small relative to the amount of power frequency. The ERA estimation algorithm and the dq-axis admittance algorithm, which can be linearized, can be employed. Moreover, the broadband oscillation problem is mainly reflected in the positive sequence component because the common broadband oscillation problem does not have the three-phase asymmetry phenomenon.
In addition, the transformation of the voltage and the current to the dq rotation coordinate system for analysis can avoid analyzing two subsynchronous components generated by the coupling of an oscillation mode on the abc coordinate system. Only the components at one frequency need be considered in the dq rotation coordinate system.
At present, a great deal of research has been carried out to show that the negative impedance characteristic generated by the new energy system is due to the negative impedance characteristic of the qq component. dd impedance is still a positive impedance characteristic similar to a current source characteristic, dq and qd impedances are relatively very small, and qq components are influenced by parameters such as PLL and a current control loop, and particularly generate larger negative impedance under certain working conditions.
Therefore, the invention only considers the qq admittance vector ordering, so that the method is more efficient when selecting the broadband oscillation source. The method comprises the steps of judging the qq axis admittance component of any station
Figure BDA0003902698000000083
When the temperature is higher than the set temperature
Figure BDA0003902698000000084
When the voltage is negative, the new energy station m is the source of the broadband oscillation, if the voltage is negative, the new energy station m is the source of the broadband oscillation
Figure BDA0003902698000000085
It means that the new energy station m has a greater contribution to the oscillation phenomenon than the other station k, and m should be preferentially removed.
In this case, the qq component admittances are ordered to obtain
Figure BDA0003902698000000086
Figure BDA0003902698000000091
Namely, it is
Figure BDA0003902698000000092
The station 1 exerts larger force on 6.28Hz oscillation than the station 2, and the judgment result is that the new energy field is firstly cut offStation 1.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.

Claims (5)

1. A broadband oscillation protection method for a new energy power system is characterized by comprising the following steps:
step 1, acquiring three-phase voltage and current of a line output end of any required new energy station in real time through a measuring device;
step 2, synchronously calculating the positive sequence frequency of the three-phase voltage through the DDSRF-PLL, and obtaining the voltage and the current on the dq rotation coordinate system;
and 3, in the real-time rolling window, performing stability judgment on the positive sequence frequency in the time period: if the oscillation judging condition is not met, returning to the step 2 to continue monitoring; if the oscillation judgment condition is met, calculating the oscillation frequency and the damping ratio, and continuing to analyze in the step 4;
step 4, calculating the admittance of the corresponding oscillation mode on the upper side through the voltage and the current on the dq axis;
and 5, judging whether the station is an oscillation source or not through the admittance of the sending end of each new energy station under the oscillation frequency, sequencing the admittance, finding out the most serious new energy station and cutting off the station.
2. The method according to claim 1, wherein the method for protecting broadband oscillation of the new energy power system comprises:
in step 3, the stability is judged to be T in total duration 0 Within a time window of, with T s For sampling frequency, the positive sequence frequency omega in the real-time window + And (6) judging the stability.
3. The method according to claim 2, wherein the method for protecting broadband oscillation of the new energy power system comprises:
the stability determination method combines two factors, firstly determines the frequency omega in the time window + Whether the difference of the local extreme values exceeds the warning value +/-Delta f lim (Hz) and the number of occurrences exceeds N p (ii) a If the conditions are met, starting a feature system implementation algorithm to calculate the positive sequence frequency omega + Middle oscillation mode frequency (f) 1 ,f 2 ,…,f N ) And damping ratio (D) 1 ,D 2 ,…,D N ) N is the number of the monitored oscillation modes; secondly, judging the stability according to the damping ratio of the oscillation mode;
at any f n Under the corresponding mode n, if the damping ratio meets 0 percent<D n <D lim If the system is in critical stability and has oscillation risk, giving out early warning to keep cutting off the new energy station and continuing monitoring; if the damping ratio of the oscillation mode satisfies D n If the frequency is less than or equal to 0%, the system generates broadband oscillation, gives out early warning and prepares for next-step new energy station cutting.
4. The method according to claim 1, wherein the method for protecting broadband oscillation of the new energy power system comprises:
in step 4, the admittance of the corresponding oscillation mode on the dq axis is calculated according to the voltage and the current on the dq axis, and the corresponding oscillation mode f is calculated on the dq axis n Voltage/current vector at, i.e. V d (f n )，V q (f n ),I d (f n ) And I q (f n ) And calculating the admittance matrix on the dq axis according to the following formula:
Figure FDA0003902697990000021
wherein M =1,2,3, \ 8230, M is the total number of the measured new energy stations; n =1,2,3, \ 8230, N is the number of oscillation modes detected.
5. The method according to claim 1, wherein the method for protecting broadband oscillation of the new energy power system comprises:
in step 5, the admittance ordering is qq-axis admittance components
Figure FDA0003902697990000022
When in use
Figure FDA0003902697990000023
When negative, the new energy station is the source of the broadband oscillation, if
Figure FDA0003902697990000024
It means that the new energy station m has a greater contribution to the oscillation phenomenon than the other station k, and m should be preferentially removed.
CN202211296164.4A 2022-10-21 2022-10-21 Broadband oscillation protection method for new energy power system Pending CN115632410A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116613751A (en) * 2023-07-19 2023-08-18 国网江西省电力有限公司电力科学研究院 Small interference stability analysis method and system for new energy grid-connected system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116613751A (en) * 2023-07-19 2023-08-18 国网江西省电力有限公司电力科学研究院 Small interference stability analysis method and system for new energy grid-connected system
CN116613751B (en) * 2023-07-19 2023-11-07 国网江西省电力有限公司电力科学研究院 Small interference stability analysis method and system for new energy grid-connected system

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