CN105098707A - Harmonic impedance protection method for direct-current filter - Google Patents
Harmonic impedance protection method for direct-current filter Download PDFInfo
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- CN105098707A CN105098707A CN201510536307.8A CN201510536307A CN105098707A CN 105098707 A CN105098707 A CN 105098707A CN 201510536307 A CN201510536307 A CN 201510536307A CN 105098707 A CN105098707 A CN 105098707A
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- harmonic impedance
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Abstract
The invention discloses a harmonic impedance protection method for a direct-current filter. The harmonic impedance protection method particularly comprises the steps as follows: the harmonic impedance at a frequency is calculated by voltage amount and current amount of a relatively small frequency at a tuning frequency of the direct-current filter; the harmonic impedance changes when the direct-current filter is in a failure; and corresponding protection criteria are provided according to the change of the harmonic impedance level when the harmonic impedance is in the failure. The voltage amount and the current amount are accessed as the protection criteria, so that the operation condition of the direct-current filter can be relatively comprehensively reflected; the harmonic impedance relatively greatly changes when the direct-current filter is in the failure on the head end; the protection sensitivity is high; the problem that differential protection sensitivity is insufficient when the filter is in the failure on the head end is solved; meanwhile, the protection can reflect the problems such as filter mismatching; and relatively comprehensive and reliable protection on the direct-current filter is realized.
Description
Technical field
The present invention relates to and be a kind ofly applied to DC filter in high voltage direct current transmission and protect new guard method.It is specifically the voltage and current amount utilizing the less frequency under the tuning frequency of DC filter; calculate the harmonic impedance under this frequency; corresponding Protection criteria is proposed according to the change of harmonic impedance when fault; this protection is applicable to single tuning, DC filter protection in the multiple high voltage direct current transmission such as double tunning.
Background technology
The general magnitude of current that adopts of current DC filter protection is as Protection criteria; harmonic current differential protection head end harmonic current when breaking down near filter head end as DC filter main protection reduces greatly; make harmonic current difference stream less; now differential protection sensitivity greatly reduces; tripping may be there is; and the unbalance protection that DC filter is equipped with also cannot react other faults except capacitive faults; and because now harmonic current reduces, so the overcurrent protection protected in support also action cannot remove surgical filtering device.
Sensitively can reliably not react the Protection criteria of DC filter near head end fault at present.
Summary of the invention
For solving the deficiency existed in the protection of existing DC filter; the present invention proposes the guard method of a kind of DC filter harmonic impedance; according to filter fault time-harmonic wave resistance value size variation, filter is protected; compensate for differential protection under-sensitive problem when near terminal fault, improve sensitivity and the reliability of DC filter protection.
For reaching above object, the present invention realizes by the following technical solutions.
The present invention to utilize under the tuning frequency of DC filter compared with the harmonic impedance of small frequency as Protection criteria; filter harmonic impedance under tuned frequency is minimum; when filter fault, resonance point offsets; the harmonic impedance of filter under tuned frequency is increased; therefore when filter harmonic impedance is greater than definite value, action, in tripping operation, carries out reliably protecting to filter:
The guard method of a kind of DC filter harmonic impedance, comprises the following steps,
(1) the voltage and current amount of DC filter, is obtained respectively by the current transformer of voltage measuring apparatus and DC filter head end, the harmonic voltage that extraction filter tuning frequency medium and low frequency is secondary respectively from described voltage and current amount and harmonic current (the low frequency refers to that the filter tuner frequency is compared, and chooses the minimum frequency);
(2), by the harmonic voltage of extraction and the harmonic impedance Z of harmonic wave Current calculation filter
k,
Z
k=U
k/ I
k, wherein Z
kfor harmonic impedance, U
kfor harmonic voltage, I
kfor harmonic current,
kfor harmonic number, judged the operating condition of filter by described harmonic impedance, as harmonic impedance Z
koff resonance alarm or tripping operation is carried out, as harmonic impedance Z when being greater than filter off resonance definite value
kwhen being greater than filter fault parametrs identification, being judged to be filter fault, tripping, surgical filtering device carries out reliably protecting to filter.
Beneficial effect of the present invention comprises:
(1) DC filter harmonic impedance protection of the present invention, based on impedance as criterion, make use of voltage and current amount simultaneously, more comprehensively reflects the operating condition of filter, makes protection more reliable.
(2) harmonic impedance chosen is protected to be under the filter tuner frequency; the harmonic impedance of the less frequency obtained of comparing; like this performance requirement of potential and current transformers is decreased; also reduce sample frequency simultaneously; reduce the live load of device, add the computational accuracy of protection.
(3) protection chooses harmonic impedance as Protection criteria; filter near head end fault time; harmonic impedance increases greatly; protection sensitivity is higher; differential protection can be made up in the defect near head end fault sensitivity deficiency; mutually can supplement with differential protection and realize more reliably protecting DC filter; protection simultaneously can also be reacted because external working environment change causes filter off resonance; protection can action in alarm; remind staff to check and improve equipment operational environment, the extension device life-span.
(4) DC filter is larger near head end fault time-harmonic wave impedance variation; protection sensitivity is high; compensate for differential protection filter near head end fault time under-sensitive problem; harmonic impedance protection can make up differential protection filter near head end fault time under-sensitive problem; also can react the problems such as filter off resonance, realize the more comprehensively perfect protection of DC filter.
Accompanying drawing explanation
Fig. 1 HP12/24 double tunning DC filter.
Embodiment
Below in conjunction with accompanying drawing, the present invention is further described.
The guard method of a kind of DC filter harmonic impedance, comprises the following steps,
(1), the voltage and current amount of DC filter is obtained respectively by the current transformer (TA1 in accompanying drawing 1) of voltage measuring apparatus (U1 in accompanying drawing 1) and DC filter head end, the harmonic voltage that the tuning frequency medium and low frequency of extraction filter is secondary respectively from described voltage and current amount and harmonic current, in the present embodiment, the filter tuner frequency is 12 times and 24 subharmonic, then adopt 12 subharmonic voltages lower in the tuning frequency and harmonic current, for the HP12/24 double tunning DC filter in accompanying drawing 1, then extract 12 subharmonic voltages in electric current and voltage amount and the harmonic wave magnitude of current.
(2), by the harmonic voltage of extraction and the harmonic impedance Z of harmonic wave Current calculation filter
k,
Z
k＝U
k/I
k，
Wherein Z
kfor harmonic impedance, U
kfor harmonic voltage, I
kfor harmonic current, k is harmonic number, and when the filter tuner frequency is 12 times and 24 subharmonic, then k gets 12 subharmonic lower in the tuning frequency, is judged the operating condition of filter by described harmonic impedance, as harmonic impedance Z
kwhen being greater than filter off resonance definite value, action is in off resonance alarm or tripping operation, as harmonic impedance Z
kwhen being greater than filter fault parametrs identification, judge filter fault, action is in tripping operation, and surgical filtering device carries out reliably protecting to filter.
The above is only the preferred embodiment of the present invention; be noted that for those skilled in the art; under the premise without departing from the principles of the invention, can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.
Claims (1)
1. the guard method of DC filter harmonic impedance, is characterized in that, comprises the following steps,
(1), the voltage and current amount of DC filter is obtained respectively by the current transformer of voltage measuring apparatus and DC filter head end, the harmonic voltage of the tuning frequency medium and low frequency of extraction filter time and harmonic current respectively from described voltage and current amount;
(2), by the harmonic voltage of extraction and the harmonic impedance Z of harmonic wave Current calculation filter
k,
Z
k＝U
k/I
k
Wherein Z
kfor harmonic impedance, U
kfor harmonic voltage, I
kfor harmonic current, k is harmonic number, is judged the operating condition of filter by described harmonic impedance, as harmonic impedance Z
koff resonance alarm or tripping operation is carried out, as harmonic impedance Z when being greater than filter off resonance definite value
kwhen being greater than filter fault parametrs identification, being judged to be filter fault, tripping, surgical filtering device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510536307.8A CN105098707A (en) | 2015-08-27 | 2015-08-27 | Harmonic impedance protection method for direct-current filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510536307.8A CN105098707A (en) | 2015-08-27 | 2015-08-27 | Harmonic impedance protection method for direct-current filter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN105098707A true CN105098707A (en) | 2015-11-25 |
Family
ID=54578586
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510536307.8A Pending CN105098707A (en) | 2015-08-27 | 2015-08-27 | Harmonic impedance protection method for direct-current filter |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109813993A (en) * | 2019-01-07 | 2019-05-28 | 西南交通大学 | A kind of recognition methods of double tunning DC filter high-voltage capacitor ground fault |
| CN110554330A (en) * | 2018-06-01 | 2019-12-10 | 通用电气公司 | Diagnostic apparatus and method for diagnosing fault conditions in a gradient amplifier system |
Citations (3)
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| CN102401866A (en) * | 2011-12-13 | 2012-04-04 | 广东电网公司佛山供电局 | Detecting method of detuning fault element of triple-tuned DC filter |
| CN103675560A (en) * | 2013-12-30 | 2014-03-26 | 武汉大学 | Online identifying method for detuning of direct current side filter of high-voltage direct current transmission system |
| CN103884948A (en) * | 2014-04-15 | 2014-06-25 | 武汉大学 | Online mistuning identification method for single-tuned filter in high-voltage direct-current power transmission system |
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2015
- 2015-08-27 CN CN201510536307.8A patent/CN105098707A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102401866A (en) * | 2011-12-13 | 2012-04-04 | 广东电网公司佛山供电局 | Detecting method of detuning fault element of triple-tuned DC filter |
| CN103675560A (en) * | 2013-12-30 | 2014-03-26 | 武汉大学 | Online identifying method for detuning of direct current side filter of high-voltage direct current transmission system |
| CN103884948A (en) * | 2014-04-15 | 2014-06-25 | 武汉大学 | Online mistuning identification method for single-tuned filter in high-voltage direct-current power transmission system |
Non-Patent Citations (2)
| Title |
|---|
| 王钢，罗慧卉，黄敏，李海锋: "基于粗糙集的三调谐直流滤波器失谐故障元件检测方法", 《电力系统自动化》 * |
| 魏春枝，张小虎: "特高压直流滤波器的失谐检测及保护", 《技术研发》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110554330A (en) * | 2018-06-01 | 2019-12-10 | 通用电气公司 | Diagnostic apparatus and method for diagnosing fault conditions in a gradient amplifier system |
| CN110554330B (en) * | 2018-06-01 | 2022-07-22 | 通用电气公司 | Diagnostic apparatus and method for diagnosing fault conditions in a gradient amplifier system |
| CN109813993A (en) * | 2019-01-07 | 2019-05-28 | 西南交通大学 | A kind of recognition methods of double tunning DC filter high-voltage capacitor ground fault |
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Application publication date: 20151125 |
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