CN108964056A - A kind of comprehensive harmonic-model construction method of electric system and its application - Google Patents
A kind of comprehensive harmonic-model construction method of electric system and its application Download PDFInfo
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- CN108964056A CN108964056A CN201811032144.XA CN201811032144A CN108964056A CN 108964056 A CN108964056 A CN 108964056A CN 201811032144 A CN201811032144 A CN 201811032144A CN 108964056 A CN108964056 A CN 108964056A
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- load
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- voltage
- construction method
- electric system
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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
- H02J3/01—Arrangements for reducing harmonics or ripples
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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
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
-
- 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
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
- H02J2003/365—Reducing harmonics or oscillations in HVDC
-
- 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]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/40—Arrangements for reducing harmonics
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The present invention relates to a kind of comprehensive harmonic-model construction method of electric system and its application, the construction method obtains load C-V characteristic the following steps are included: the 1) instantaneous voltage and transient current of real-time measurement load；2) it is calculated by fundamental load flow, is superimposed background harmonic voltage, obtains the fundamental wave supply voltage of load supply terminals；3) according to the fundamental wave supply voltage and load C-V characteristic, sampling obtains load current waveform；4) FFT is carried out to load current sampled value, obtains each component of degree n n of harmonic current, realizes the building of the harmonic-model of some node.Compared with prior art, the present invention has many advantages, such as that practicability is good, can meet all kinds of harmonic source occasions.
Description
Technical field
The present invention relates to technical field of electric power, more particularly, to a kind of comprehensive harmonic-model construction method of electric system and
It is applied.
Background technique
High voltage direct current (HVDC) transmission of electricity due to its transmission distance limit by the stability run simultaneously, transmission capacity greatly,
The advantages that small, power regulation rapid flexible is lost, economizes the land resource, long-distance and large-capacity power transmission, gorge over strait power transmissions and
Asynchronous networking of power grid etc. has obtained very extensive application.When twice and with last time D.C. high voltage transmission drop point in same
When one AC system, the DC power transmission system being consequently formed is referred to as multi-infeed HVDC (Multi-Infeed Direct
Current, MIDC) transmission system, which is known as the power grid containing Multi-infeed HVDC transmission system, straight comprising more feed-ins
The interconnection system of stream transmission system and accessed AC system is referred to as more feed-in alternating current-direct current (Multi-Infeed Direct
Current&Alternative Current, MIDC-AC) transmission system.
High voltage direct current transmission device based on thyristor is the harmonic source of a nonlinearity.In operational process, change
Flow device to power grid injecting power very big, harmonic components low-order harmonic abundant, and it is humorous to generate on change of current bus corresponding background
Wave voltage.Certain specific run modes that alternating current filter and AC system may be caused generate Harmonics amplification, or even in parallel humorous
Vibration.These harmonic waves cause harmonic pollution to power grid, endanger the safety of electrical equipment, while reducing the economic benefit of power grid, and frequency
Low-order harmonic influence to electrical equipment of the rate less than 20kHz is mainly: 1. Harmonics amplification even resonance, jeopardize electrical equipment and
The safety of personnel；2. causing apparatus overheat, the lost of life since added losses increase；3. aggravating slewing mechanical oscillation.
It is therefore necessary to study network system harmonic wave, and the harmonic source simulation model for how preferably establishing high-pressure system is one
A technical issues that need to address.
Summary of the invention
It is comprehensive that it is an object of the present invention to overcome the above-mentioned drawbacks of the prior art and provide a kind of electric system
Property harmonic-model construction method and its application.
The purpose of the present invention can be achieved through the following technical solutions:
A kind of comprehensive harmonic-model construction method of electric system, comprising the following steps:
1) instantaneous voltage and transient current of real-time measurement load obtains load C-V characteristic；
2) it is calculated by fundamental load flow, is superimposed background harmonic voltage, obtains the fundamental wave supply voltage of load supply terminals；
3) according to the fundamental wave supply voltage and load C-V characteristic, sampling obtains load current waveform；
4) FFT is carried out to load current sampled value, obtains each component of degree n n of harmonic current, realizes the harmonic wave mould of some node
The building of type.
Further, the load is nonlinear-load or synthetic load.
Further, in the step 1), the instantaneous voltage and transient current of load is repeatedly measured, averaged is passed through
Mode obtain load C-V characteristic.
Further, the supply voltage is pure sine wave voltage or non-sinusoidal waveform voltage.
Further, when the supply voltage is non-sinusoidal waveform voltage, step 2) further include: FFT is carried out to supply voltage
Transformation, obtains the phase and amplitude of fundamental voltage；
Further, in step 3), using the fundamental voltage and load C-V characteristic, sampling obtains load current wave
Shape.
A kind of high-pressure system Harmonic characteristic analysis method based on the comprehensive harmonic-model of electric system, the electric system
Comprehensive harmonic-model is constructed by construction method as mentioned.
Compared with prior art, the invention has the following advantages:
(1) practicability of the present invention is good, can meet all kinds of harmonic source occasions, be saved.
(2) present invention can be accumulated the Harmonic source model of each node under different operating conditions by season, the method for operation.
(3) model of the invention can be applied to all kinds of offline frequency analyses, it is only necessary to and it carries out conventional fundamental load flow and calculates,
Each node corresponding to the tidal current analysis result can be provided according to the result of Load flow calculation and the Harmonic source model of each node
Harmonic characteristic.
(4) present invention is when obtaining the fundamental wave supply voltage of load supply terminals, it is contemplated that background harmonic voltage improves essence
Exactness.
(5) present invention is according to different fundamental load flow distribution results, providing corresponding harmonic voltage, electric current in engineering
Level distribution does not need other more complicated frequency analyses.
(6) present invention has hidden high pressure merely with fundamental voltage, just, extra high voltage system widely applies CVT and can not be just
The shortcomings that really obtaining voltage true waveform has wide applicability in high pressure, extra-high voltage system.
Detailed description of the invention
Fig. 1 is flow diagram of the invention.
Specific embodiment
The present invention is described in detail with specific embodiment below in conjunction with the accompanying drawings.The present embodiment is with technical solution of the present invention
Premised on implemented, the detailed implementation method and specific operation process are given, but protection scope of the present invention is not limited to
Following embodiments.
As shown in Figure 1, the present invention provides a kind of comprehensive harmonic-model construction method of electric system, comprising the following steps:
S101, the instantaneous voltage and transient current of real-time measurement load obtain load C-V characteristic, and the load is non-thread
Property load or synthetic load.
In certain embodiments, the instantaneous voltage and transient current that can repeatedly measure load, pass through the side of averaged
Formula obtains load C-V characteristic.
S102 is calculated by fundamental load flow, is superimposed background harmonic voltage, is obtained the fundamental wave supply voltage of load supply terminals；
S103, according to the fundamental wave supply voltage and load C-V characteristic, sampling obtains load current waveform；
S104 carries out FFT to load current sampled value, obtains each component of degree n n of harmonic current, realize the humorous of some node
The building of wave pattern.
Supply voltage can be pure sine wave voltage or non-sinusoidal waveform voltage.
1) supply voltage is pure sine wave
Supply voltage: u (t)=sin (wt), w=2 π f, f=50Hz；
Sample the load current obtained:
I (t)=0.8sin (wt+ pi/2)+0.1sin (2wt)+0.3sin (5wt+ pi/2)+0.2sin (7wt+3 pi/2)
Each primary current frequency spectrum numerical value calculated by FFT is as shown in table 1, coincide very much with theoretical value.
Identification result under 1 sinusoidal voltage of table
| Number | 1 | 2 | 3 | 5 |
| Amplitude | 0.8 | 0.1 | 0.3 | 0.2 |
| Phase (degree) | 90 | 5.57E-14 | 90 | -90 |
2) supply voltage is non-sinusoidal waveform
When supply voltage is non-sinusoidal waveform voltage, step 2) further include: FFT transform is carried out to supply voltage, obtains fundamental wave
The phase and amplitude of voltage；Simultaneously in step 3), using the fundamental voltage and load C-V characteristic, sampling obtains load electricity
Flow waveform.The above process can correct modeling process, to improve accuracy.
Voltage u (t)=sin (wt)+0.03sin (3wt+pi/6)+0.02*sin (5wt), w=2 π f, f=50Hz；
Sample the electric current obtained:
I (t)=0.8sin (wt+ pi/2)+0.1sin (2wt)+0.3sin (5wt+ pi/2)+0.2sin (7wt+3 pi/2)
Identification result under non-sinusoidal voltage after table 2 is corrected
Above-mentioned harmonic-model construction method has the following characteristics that
1) the harmonic current source model library that can establish each node, is saved；
2) Harmonic source model of each node under different operating conditions can be accumulated by season, the method for operation；
3) model built can be applied to all kinds of offline frequency analyses, it is only necessary to and it carries out conventional fundamental load flow and calculates,
According to the result of Load flow calculation and the Harmonic source model of each node, the harmonic wave of each node corresponding to the tidal current analysis result is provided
Feature.
4) harmonic current is utilized, each point harmonic voltage that solution can be facilitated to obtain corresponding to trend distribution is horizontal.
The present embodiment also provides a kind of high-pressure system Harmonic characteristic analysis side based on the comprehensive harmonic-model of electric system
Method, the comprehensive harmonic-model of electric system are constructed by construction method as mentioned, which mainly uses fundamental wave electric
Pressure, this point has just hidden high pressure, extra high voltage system widely applies CVT and the shortcomings that can not correctly obtain voltage true waveform,
There is wide applicability in high pressure, extra-high voltage system.
The preferred embodiment of the present invention has been described in detail above.It should be appreciated that those skilled in the art without
It needs creative work according to the present invention can conceive and makes many modifications and variations.Therefore, all technologies in the art
Personnel are available by logical analysis, reasoning, or a limited experiment on the basis of existing technology under this invention's idea
Technical solution, all should be within the scope of protection determined by the claims.
Claims (6)
1. a kind of comprehensive harmonic-model construction method of electric system, which comprises the following steps:
1) instantaneous voltage and transient current of real-time measurement load obtains load C-V characteristic；
2) it is calculated by fundamental load flow, is superimposed background harmonic voltage, obtains the fundamental wave supply voltage of load supply terminals；
3) according to the fundamental wave supply voltage and load C-V characteristic, sampling obtains load current waveform；
4) FFT is carried out to load current sampled value, obtains each component of degree n n of harmonic current, realizes the harmonic-model of some node
Building.
2. the comprehensive harmonic-model construction method of electric system according to claim 1, which is characterized in that the load is
Nonlinear-load or synthetic load.
3. the comprehensive harmonic-model construction method of electric system according to claim 1, which is characterized in that the step 1)
In, the instantaneous voltage and transient current of load are repeatedly measured, load C-V characteristic is obtained by way of averaged.
4. the comprehensive harmonic-model construction method of electric system according to claim 1, which is characterized in that the power supply electricity
Pressure is pure sine wave voltage or non-sinusoidal waveform voltage.
5. the comprehensive harmonic-model construction method of electric system according to claim 4, which is characterized in that the power supply electricity
When pressure is non-sinusoidal waveform voltage, step 2) further include: FFT transform is carried out to supply voltage, obtains the phase and width of fundamental voltage
Value；
In step 3), using the fundamental voltage and load C-V characteristic, sampling obtains load current waveform.
6. a kind of high-pressure system Harmonic characteristic analysis method based on the comprehensive harmonic-model of electric system, which is characterized in that institute
The comprehensive harmonic-model of electric system is stated to construct by construction method as described in claim 1.
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| CN201811032144.XA CN108964056A (en) | 2018-09-05 | 2018-09-05 | A kind of comprehensive harmonic-model construction method of electric system and its application |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5499178A (en) * | 1991-12-16 | 1996-03-12 | Regents Of The University Of Minnesota | System for reducing harmonics by harmonic current injection |
| CN103954859A (en) * | 2014-04-16 | 2014-07-30 | 国网上海市电力公司 | Harmonic current characteristic analysis method based on given voltage of harmonic source model |
-
2018
- 2018-09-05 CN CN201811032144.XA patent/CN108964056A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5499178A (en) * | 1991-12-16 | 1996-03-12 | Regents Of The University Of Minnesota | System for reducing harmonics by harmonic current injection |
| CN103954859A (en) * | 2014-04-16 | 2014-07-30 | 国网上海市电力公司 | Harmonic current characteristic analysis method based on given voltage of harmonic source model |
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Effective date of registration: 20190415 Address after: Room 1301, Building 430-1, Xujiahui Road, Huangpu District, Shanghai 200025 Applicant after: Shanghai Hengnengtai Enterprise Management Co., Ltd. Applicant after: State Grid Shanghai Municipal Electric Power Company Address before: 200437 No. 171, Handan Road, Shanghai, Hongkou District Applicant before: Shanghai Sai Pu Le Power Technology Co. Ltd. Applicant before: State Grid Shanghai Municipal Electric Power Company |
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Application publication date: 20181207 |
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