CN203672975U - Harmonic-impedance measuring device for power system - Google Patents
Harmonic-impedance measuring device for power system Download PDFInfo
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- CN203672975U CN203672975U CN201320717116.8U CN201320717116U CN203672975U CN 203672975 U CN203672975 U CN 203672975U CN 201320717116 U CN201320717116 U CN 201320717116U CN 203672975 U CN203672975 U CN 203672975U
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- 238000000034 method Methods 0.000 claims abstract description 10
- 239000003990 capacitor Substances 0.000 claims abstract description 6
- 238000004146 energy storage Methods 0.000 claims abstract description 6
- 238000002847 impedance measurement Methods 0.000 claims description 10
- 238000002347 injection Methods 0.000 claims description 3
- 239000007924 injection Substances 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 3
- 238000005259 measurement Methods 0.000 abstract description 5
- 238000004364 calculation method Methods 0.000 abstract description 3
- 238000004458 analytical method Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000007405 data analysis Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
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Abstract
The utility model discloses a harmonic-impedance measuring device for a power system, and a transformer (T) is connected with a public power grid (P). A harmonious-impedance measuring apparatus (NHID) is connected with three phases of a low voltage side of the transformer (T). The NHID consists of a harmonic injector (ID), a control unit (CD), a power unit (SU), and a measurement and calculation unit (MCM). The harmonic injector (ID) consists of a direct-current energy-storage capacitor C, a high-power electronic switch S1, a high-power electronic switch S2, a high-power electronic switch S3, a high-power electronic switch S4, a high-power electronic switch S5, a high-power electronic switch S6, and a three-phase boosting transformer (Ts1). The injecting process of the harmonic injector (ID) can be completely controlled. The device provided by the utility model can accurately measure the calculated harmonic impedance of the system, and provides reliable parameters of the harmonic impedance for the harmonic treatment.
Description
Technical field
The utility model relates to a kind of Harmonious Waves in Power Systems impedance measurement device.
Background technology
Power Electronic Technique has obtained development at full speed in recent years, strong support is provided to the technology such as improvement and EHV transmission and direct current transportation of power system power supply performance, is applied in more and more widely the every field of national economy.But in electrical network, power electronic equipment, as a nonlinear load, becomes harmonic source important in electrical network.
In order to control the harmonic pollution in utility network, standard GB/T/T 14549-93 " quality of power supply utility network harmonic wave " has specified user's harmonic emissions limit value, need the key issue solving is how at PCC, system and user's harmonic emission level reasonably to be assessed, main still around system and user's harmonic impedance is estimated to launch for the estimation of harmonic emission level.For cleaning system, normally utilize circuit resonance principle installing filter to suppress higher hamonic wave.In the situation that obtaining Harmonious Waves in Power Systems impedance, can better design and the parameter of Optimal Filter, to reach the filter effect meeting the demands.
Because harmonic impedance is for the vital role of harmonic wave control and harmonic management, correlation technique and device that therefore necessary exploitation harmonic impedance is measured.Conventional harmonic impedance measuring method is mainly the Return Law and undulate quantity method etc. at present, but they are all easily subject to the interference of background harmonics, in the situation that background harmonics fluctuation is larger, and the likely distortion of its assessment result.
Characteristic harmonics refers to the harmonic wave that system produces while normally operation, and it is that frequency is the intrinsic harmonic signal of fundamental frequency integral multiple, and uncharacteristic harmonics i.e. the frequency harmonics of other except characteristic harmonics.
Utility model content
The purpose of this utility model is to provide a kind of Harmonious Waves in Power Systems impedance measurement device of measuring.The key issue solving is in the situation that not affecting the normal operation of electric system, and accurate measurement calculates system harmonic impedance, for harmonic wave control provides reliable harmonic impedance parameter.
In harmonic impedance is measured, select rational injection device can make measurement result degree of accuracy higher and drop to minimum on the impact of electrical network, the utility model solves its technical matters, the technical scheme adopting is, transformer T connects utility network P, harmonic impedance measurement device NHID connection transformer T low-pressure side A, B, C three-phase; Harmonic impedance measurement device NHID is by harmonic wave injector ID, control module CD, power supply unit SU and measure computing unit MCM composition; Harmonic wave injector ID is by DC energy storage capacitor C, high-power electric and electronic switch S 1 ~ S6, and three-phase voltage increasing transformer Ts1 forms, and its injection process is completely controlled.
Principle of work of the present utility model is:
The T of electric substation is by utility grid, and power supply provides DC support power supply to harmonic wave injector ID, and guarantee DC energy storage capacitor C powers on and is pressed in normal range, while measuring harmonic impedance, first control module CD sends instruction to harmonic wave injector ID, harmonic wave injector ID is to transformer T low-pressure side A, B, C three-phase injects the uncharacteristic harmonics of characteristic frequency ± 10Hz scope successively, measure computing unit MCM successively to decanting point near transformer T low-pressure side A1, B1, C1 voltage and current data and close load side A2, B2, C2 data are carried out survey record, respectively to A1, B1, C1 measurement point and A2, B2, the data analysis of C2 measurement point is calculated, can obtain respectively system impedance and user's impedance of near 20 the non-characteristic frequencies of characteristic frequency, 20 non-characteristic frequency impedances that obtain are obtained to system and user characteristics frequency impedance by method of interpolation.
compared with prior art, the beneficial effects of the utility model are:
One, the utility model is with respect to traditional Return Law and undulate quantity method, harmonic wave injector is all completely adjustable in each harmonic frequency and amplitude, avoid in some frequency range relative harmonic content too low and cause that harmonic impedance assesses inaccurate situation, measured spectral range very wide.
Two, the utility model injects uncharacteristic harmonics in system, less to the normal influence on system operation of system, and can not be subject to the interference of background harmonics, and simultaneously because signal to noise ratio (S/N ratio) is very high, installed capacity requires relatively little, has reduced investment and operating cost.
Three, in the utility model, measure the ingredient that computing unit can be used as electric substation's electric energy quality monitoring system and realize Real-time Collection and the analysis to electric substation's current and voltage data.
Below in conjunction with the drawings and specific embodiments, the utility model will be further described.
Brief description of the drawings
Fig. 1 is the structural representation of the utility model embodiment.
Fig. 2 is the structural representation of the harmonic wave injector (ID) of the utility model embodiment.
Embodiment
Embodiment
Fig. 1,2 illustrates, a kind of embodiment of the present utility model is:
A kind of Harmonious Waves in Power Systems impedance means of measuring.Transformer T connects utility network P, harmonic impedance measurement device NHID connection transformer T low-pressure side A, B, C three-phase.Harmonic impedance measurement device NHID is by harmonic wave injector ID, control module CD, power supply unit SU and measure computing unit MCM composition.
Fig. 1 illustrates, the course of work of the present utility model and principle of work are: electric system characteristic harmonics is 3 times (150Hz), 5 times (250Hz), 7 times (350Hz) etc.In the time measuring 3 (150Hz) harmonic impedances of electrical network, first control module CD sends instruction to harmonic wave injector ID, harmonic wave injector ID injects 149Hz uncharacteristic harmonics to transformer T low-pressure side A, B, C three-phase, measure computing unit MCM decanting point is carried out to survey record near transformer T low-pressure side A1, B1, C1 three-phase voltage and current data and decanting point near load side A2, B2, C2 three-phase voltage and current data, A1, B1, C1 three-phase voltage and current data are carried out to analytical calculation and draw 149Hz system impedance Z
31and A2, B2, C2 three-phase voltage and current data are carried out to analytical calculation draw 149Hz user's side impedance Z
31 ,.Control module CD sends instruction again to harmonic wave injector ID, harmonic wave injector ID injects 151Hz uncharacteristic harmonics to transformer (T) low-pressure side A, B, C three-phase, measure computing unit MCM electric current and voltage data are carried out to survey record, analysis meter calculates 151Hz system impedance Z
32with user's side impedance Z
32 ,.In like manner, system harmonic impedance and the user-side harmonic impedance of 140Hz ~ 148Hz, 152Hz ~ 159Hz can be obtained, 3 (150Hz) harmonic impedance Z of system can be obtained by method of interpolation
3with user's side 3 subharmonic impedance Z
3 ,.In like manner, can obtain the characteristic harmonics impedance of other 5 times or 7 inferior systems and user's side.
Fig. 2 illustrates, in the utility model harmonic wave injector ID by DC energy storage capacitor C, high-power electric and electronic switch S 1 ~ S6, three-phase voltage increasing transformer Ts1 forms.DC energy storage capacitor C is used for storing power supply unit energy, provides work required direct supply to S1 ~ S6.S1 ~ S6 is operated in inverter mode, and single-phase electricity is reverse into the adjustable three-phase alternating current of frequency by it.S1 ~ S6 is IGCT(integrated gate commutated thyristor) or IGBT (igbt).
Claims (1)
1. a Harmonious Waves in Power Systems impedance measurement device, is characterized in that:
Transformer (T) connects utility network (P), harmonic impedance measurement device (NHID) connection transformer (T) low-pressure side A, B, C three-phase; Harmonic impedance measurement device NHID is by harmonic wave injector (ID), control module (CD), power supply unit (SU) and measure computing unit (MCM) composition; Harmonic wave injector (ID) is by DC energy storage capacitor C, high-power electric and electronic switch S 1 ~ S6, and three-phase voltage increasing transformer (Ts1) forms, and its injection process is completely controlled.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320717116.8U CN203672975U (en) | 2013-11-13 | 2013-11-13 | Harmonic-impedance measuring device for power system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320717116.8U CN203672975U (en) | 2013-11-13 | 2013-11-13 | Harmonic-impedance measuring device for power system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203672975U true CN203672975U (en) | 2014-06-25 |
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| CN201320717116.8U Expired - Lifetime CN203672975U (en) | 2013-11-13 | 2013-11-13 | Harmonic-impedance measuring device for power system |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103605002A (en) * | 2013-11-13 | 2014-02-26 | 云南电网公司电网规划研究中心 | Harmonic impedance measurement apparatus of electric power system |
| CN105699779A (en) * | 2015-12-31 | 2016-06-22 | 北京交通大学 | Cascaded H-bridge type traction network impedance test harmonic generator and test method |
| CN106443185A (en) * | 2015-08-05 | 2017-02-22 | 艾默生网络能源有限公司 | Three-phase AC system impedance measurement method and device |
-
2013
- 2013-11-13 CN CN201320717116.8U patent/CN203672975U/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103605002A (en) * | 2013-11-13 | 2014-02-26 | 云南电网公司电网规划研究中心 | Harmonic impedance measurement apparatus of electric power system |
| CN106443185A (en) * | 2015-08-05 | 2017-02-22 | 艾默生网络能源有限公司 | Three-phase AC system impedance measurement method and device |
| CN106443185B (en) * | 2015-08-05 | 2018-12-21 | 维谛技术有限公司 | A kind of measurement method and device of the impedance of three-phase alternating current system |
| CN105699779A (en) * | 2015-12-31 | 2016-06-22 | 北京交通大学 | Cascaded H-bridge type traction network impedance test harmonic generator and test method |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20140625 |