CN103219712A - Power transmission line one-phase malfunction property identification method based on natural frequency - Google Patents
Power transmission line one-phase malfunction property identification method based on natural frequency Download PDFInfo
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- CN103219712A CN103219712A CN2013100772835A CN201310077283A CN103219712A CN 103219712 A CN103219712 A CN 103219712A CN 2013100772835 A CN2013100772835 A CN 2013100772835A CN 201310077283 A CN201310077283 A CN 201310077283A CN 103219712 A CN103219712 A CN 103219712A
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Abstract
The invention discloses a power transmission line one-phase malfunction property identification method based on a natural frequency. The power transmission line one-phase malfunction property identification method based on the natural frequency includes the following steps: 1) collecting current i(t) of a malfunction phase after power transmission line one-phase malfunction trip happens, Prony analysis is carried out after the current i(t) is through signal conditioning steps such as high-pass filtering, and extracting a natural frequency dominant frequency f1(k) of transient components from a Prony analysis result; 2) comparing the natural frequency dominant frequency f1(k) acquired in the step 1) with a electric system power frequency f0(k), constructing reasonable criterion and then judging according to the criterion which is f1(k) > Kre * f0(k); and 3) carrying out power transmission line one-phase malfunction property identification according to the criterion constructed in the step 2). According to the fault-free identification method, the problems that an existing power transmission line one-phase malfunction identification method is easily affected by an electric arc model, malfunction time, line lengths, load current, transition resistance and compensation degrees are solved, and the problem that an existing recloser with fixed time limit overlaps non-failure arc transient fault is also solved, and sensitivity and reliability of the criterion of the power transmission line one-phase malfunction property identification are further improved.
Description
Technical field
The invention belongs to the power system transmission line technical field of relay protection, relate to a kind of transmission line single-phase intelligent reclosing nature of trouble method of discrimination, be specifically related to a kind of transmission line single-phase fault property identification method based on natural frequency.
Background technology
As everyone knows, the reclosing technology is a kind of effective measures that improve the transmission line power supply reliability that domestic and international electric power system extensively adopts, and fixes the danger that there is the second short circuit impact that blindly coincides with the initiation of not blow-out fault and permanent fault in the reclosing technology that overlaps the time limit but have now.In view of the requirement of intelligent grid height power supply reliability, the fault self-recovery ability that improves transmission line has important engineering and is worth, and is wherein particularly important to the research of intelligent reclosing with nature of trouble recognition function and self adaptation reclosing time.
At present, the nature of trouble method of discrimination of existing intelligent reclosing can be divided into based on fault electric arc stage electric parameters and recovery voltage stage electric parameters feature two classes.The electric arc stage method mainly is to utilize the high order harmonic component feature realization transient fault of arc voltage and the identification of permanent fault, but be difficult to set up accurate electric arc model and the low problem of small-signal certainty of measurement owing to exist, make and utilize the criterion of electric arc stage electric parameters feature to be restricted, and still there is uncertain factor in differentiate for whether fault electric arc before coincidence of instantaneity extinguishes.The method of discrimination in recovery voltage stage utilizes the terminal voltage amount and utilizes the magnitude of current two classes.The Fault Identification of utilizing voltage is mainly according to the amplitude phase property that disconnects phase voltage and the composition of harmonic wave; Utilize the Fault Identification of the magnitude of current to mainly contain the criterions such as amplitude, frequency and beat frequency characteristic that disconnect phase current, shunt reactor electric current and little reactor current.And the band and the length of mending reactor apart from spy/superhigh pressure long distance transmission line in order to reduce the single phase ground fault arc current, introducing the little reactor of neutral point realizes the approximate of alternate capacitive coupling electric current compensated entirely, utilize the current in the fault point feature to realize that the nature of trouble differentiation has difficulties, and high compensativity shunt reactor has slackened the coupling that perfects phase greatly, cause low frequency self-vibration component frequency after the transient fault blow-out very near power frequency component simultaneously, make and utilize the method for discrimination of beat frequency feature to be difficult to effective application.
Summary of the invention
The object of the present invention is to provide a kind of transmission line single-phase fault property identification method, further improved the sensitivity and the reliability of transmission line single-phase fault identical criterion based on natural frequency.
The technical solution adopted in the present invention is based on the transmission line single-phase fault property identification method of natural frequency, specifically to implement according to following steps:
Step 1 after the tripping operation of transmission line single-phase fault, is gathered fault phase current i (t), again fault phase current i (t) is carried out PRONY earlier behind signal condition and analyzes, and obtains fault phase current i (t) dominant frequency frequency f
1(k);
Step 2 is with the dominant frequency frequency f of obtaining in the step 1
1(k) with electric power system power frequency f
0(k) compare, construct rational criterion;
Step 3 is carried out transmission line single-phase fault property identification according to the criterion of step 2 structure.
Characteristics of the present invention also are,
Step 1 is specifically implemented according to following steps:
Step 1.1, fault phase current i (t) is gathered in transmission line single-phase fault tripping operation back;
Step 1.2 is carried out signal processing such as high-pass filtering to the fault phase current i (t) that collects in the step 1.1;
Step 1.3 is carried out PRONY to the fault phase current i (t) after step 1.2 processing and is analyzed, and extracts the natural frequency dominant frequency frequency f that contains transient state component among the fault phase current i (t) in the PRONY analysis result
1(k).
The criterion that makes up in the step 2 is:
f
1(k)>K
re·f
0(k)；
State in the criterion K
ReBe safety factor, K
Re1.
Step 3 is specifically implemented according to following steps:
After if circuit breaker disconnects, as if the criterion requirement of satisfying in the step 2, can reliably be judged to transmission line single-phase fault character is transient fault;
Otherwise then being judged to transmission line single-phase fault character is permanent fault.
Beneficial effect of the present invention is,
(1) the transmission line single-phase fault property identification method based on natural frequency of the present invention is when transmission line breaks down, the capable ripple that fault produces will come back reflective between fault point and circuit two ends, the both sides, fault point all can be realized the identification to nature of trouble separately; For important transmission line, the circuit two ends can be differentiated simultaneously, play the effect of confirming again after the judgement, can effectively guarantee the reliability of nature of trouble identical criterion.
(2) there are power frequency and natural frequency composition in the transient state component of transmission line single-phase fault property identification method after fault takes place based on natural frequency of the present invention, natural frequency is higher than power frequency, and dominant frequency and power frequency (50Hz) are the most approaching in all natural frequencys, signal amplitude is big and life period is longer, is easy to extract; If after circuit breaker disconnected, natural frequency dominant frequency component does not exist or life period is less can't extract then transmission line generation permanent fault and blow-out.
(3) of the present invention based on the intrinsic main frequency of transmission line malfunction generation in the transmission line single-phase fault property identification method of natural frequency and the intrinsic relating to parameters of transmission lines such as impedance of position of failure point and circuit two end systems, be not subjected to the influence of factors such as system running state, electric arc model, fault moment, line length, load current, transition resistance and compensativity.
(4) the transmission line single-phase fault property identification method based on natural frequency of the present invention has favorable applicability, for existing band shunt reactor and all not applicable with the transmission line of shunt reactor.
Description of drawings
Fig. 1 is the structure chart of the transmission line Microcomputer-based Protection Hardware of the two ends band shunt reactor that adopts in the transmission line single-phase fault property identification method based on natural frequency of the present invention;
Fig. 2 is the sequential chart that transmission line breaks down.
Embodiment
The present invention is described in detail below in conjunction with the drawings and specific embodiments.
After ultra-high-tension power transmission line broke down, the cyclical component in the high fdrequency component was that the row ripple is propagated on transmission line after breaking down, and between fault point and source impedance, reflect to form back and forth.On frequency domain, show as the harmonic wave form of a characteristic frequency (being the natural frequency dominant frequency).Form the oscillation circuit of natural frequency by line inductance and line mutual-ground capacitor, because the distributed constant characteristic of transmission line, natural frequency should have infinite a plurality of.Along with the increase of natural frequency, it is more and more serious to decay, and the natural frequency component amplitude is more and more littler, and when having only the dominant frequency amplitude maximum of natural frequency, frequency and power frequency are the most approaching.
In the inventive method the transmission line of two ends band shunt reactor is studied; as shown in Figure 1; the protective device that uses discriminating element of the present invention is equipped with in transmission line M, N both sides; input variable is the transmission line magnitude of current; electric current is obtained by transmission line both sides current transformer TA1, TA2; in the frame of broken lines among Fig. 1 is hardware structure diagram of the present invention; this hardware includes data acquisition system, microcomputer main system and output output system, and the differentiation algorithm in the inventive method is realized in microcomputer DSP main system by programming.With the M side is example, the transmission line electric current through current transformer TA1 obtain after high-pass filtering, sampling keep and the A/D conversion after, deliver to the microcomputer main system, go out natural frequency by corresponding algorithm computation; Judge that according to the calculation on Natural Frequency result single-phase fault that circuit takes place is transient fault or permanent fault then.In like manner, also can judge circuit single-phase fault character for the protective device of both-end band shunt reactor circuit N side according to aforementioned thinking.Differentiating the result for an end band shunt reactor circuit can be by channel transfer to the opposite end, is that the differentiation result of criterion determines the two ends reclosing whether to move by the differentiation algorithm.
The principle of the transmission line single-phase fault property identification method based on natural frequency of the present invention is to utilize the frequency characteristic of fault phase current amount to make up the nature of trouble identical criterion, specifically be that current component in the fault circuit is successively after record ripple, filtering, utilize its frequency of Prony Algorithm Analysis, extract natural frequency main frequency component, set up the nature of trouble identical criterion by the size that compares dominant frequency and power frequency and carry out nature of trouble identification.
Transmission line single-phase fault property identification method based on natural frequency of the present invention, specifically implement according to following steps:
Step 1 after the tripping operation of transmission line single-phase fault, is gathered fault phase current i (t), again fault phase current i (t) is carried out Prony earlier behind signal condition and analyzes, and obtains fault phase current i (t) dominant frequency frequency f
1(k):
Step 1.1, fault phase current i (t) is gathered in transmission line single-phase fault tripping operation back;
Step 1.2 is carried out signal processing such as high-pass filtering to the fault phase current i (t) that collects in the step 1.1, and filtering noise and frequency are lower than each frequency signal of 50Hz;
Step 1.3 is carried out Prony to the fault phase current i (t) after step 1.2 processing and is analyzed, and extracts the natural frequency dominant frequency frequency f of the transient state component that contains among the fault phase current i (t) in the Prony analysis result
1(k); This is that it is serious more to decay, and has only natural frequency dominant frequency component amplitude the highest because the high more amplitude of each transient state component medium frequency that fault phase current i (t) contains is little, and it is the most convenient to extract, and the dominant frequency frequency f
1(k) with power frequency f
0(k) the most approaching;
Step 2 is with the dominant frequency frequency f of obtaining in the step 1
1(k) with electric power system power frequency f
0(k) compare, construct rational criterion:
After the tripping operation of transmission line single-phase fault, there is natural frequency high frequency transient component in fault phase current i (t) component, and dominant frequency frequency f in the natural frequency
1(k) can be greater than electric power system power frequency f
0(k);
After circuit breaker disconnects, transient fault (fault is blow-out not) the natural frequency high fdrequency component that also can exist;
Permanent fault is reliably discharge over the ground, and fault phase current i (t) component does not exist high fdrequency component only to have power frequency component f
0(k);
Specifically judge according to following criterion:
f
1(k)>K
re·f
0(k)；
In above-mentioned criterion, K
ReBe safety factor, K
Re1;
Step 3, carry out transmission line single-phase fault property identification according to the criterion of step 2 structure:
After circuit breaker disconnects, if satisfy the criterion requirement in the step 2, can reliably be judged to transmission line single-phase fault character is transient fault, the moment that produces the transient fault blow-out is sent the coincidence order, can effectively shorten interruption duration like this, the moment of transient fault blow-out is effectively improved the efficient of reclosing really surely;
Otherwise, then to be judged to transmission line single-phase fault character be permanent fault or be referred to as transient fault blow-out, before allowing the open-phase operation time to arrive, maximum continues to differentiate, permanent fault reliably discharge over the ground in addition, arc extinction is very fast relatively, after circuit breaker disconnected, fault did not contain the high frequency proper component mutually.
Fig. 2 has showed the transmission line malfunction sequential, as seen from Figure 2: t
1Transmission line breaks down t constantly
2Circuit breaker disconnects constantly, t
3Fault blow-out constantly, t
4It is the reclosing moment.After transmission line malfunction takes place, i.e. t〉t
1The time, to the dominant frequency f of fault phase transient state current component natural frequency
1(k) continue to calculate,, after the reclosing device action, stop to calculate when judgement is finished.Work as t
1＜t＜t
2The time, transient fault and permanent fault all contain the transient high frequency component; Because permanent fault is reliably discharge over the ground, the natural frequency dominant frequency component duration is not long in the fault phase transient state component.Work as t〉t
2The time, can be according to criterion failure judgement character, if can't extract intrinsic high frequency dominant frequency component or dominant frequency component and do not exist the time, can directly be judged to permanent fault.When satisfying operation condition, above-mentioned criterion is judged to transient fault, adaptive reclose device action, breaker closing.Otherwise, then be judged to permanent fault, the locking of adaptive reclose device.
Method of the present invention is on transmission line internal fault basis, electromagnetic wave natural frequency according to the fault generation, analyze the natural frequency feature and propose a kind of transmission line malfunction property identification method based on the natural frequency feature, wherein natural frequency only with the intrinsic relating to parameters of transmission line, so the method is not subjected to the influence of other factors outside the system, is used with the existing criterion of utilizing transmission line electric parameters feature and can effectively improves reliability.Method of the present invention not only can be used as the effective ways of ultra high voltage long transmission line intelligence reclosing nature of trouble identification; Also can be used as existing effectively replenishing based on fault phase electric parameters characteristic criterion.On the increasingly mature basis of Microcomputer Protection and signal processing technology, this method has a good application prospect.
Transmission line malfunction property identification method based on the natural frequency feature of the present invention is based on the dominant frequency composition that the fault point produces a series of transient high frequency (being natural frequency) component of propagating to the transmission line both sides, after circuit breaker disconnects, according to natural frequency dominant frequency frequency f
1(k) with the power frequency size relatively discern nature of trouble, natural frequency has only relevant with transmission line parameter characteristics, has avoided based on the relevant shortcoming that certainty of measurement is had relatively high expectations that reaches with multiple factor of the fault phase electric parameters of fault phase electric parameters feature identification criterion.
Claims (4)
1. based on the transmission line single-phase fault property identification method of natural frequency, it is characterized in that, specifically implement according to following steps:
Step 1 after the tripping operation of transmission line single-phase fault, is gathered fault phase current i (t), again fault phase current i (t) is carried out PRONY earlier behind signal condition and analyzes, and obtains fault phase current i (t) dominant frequency frequency f
1(k);
Step 2 is with the dominant frequency frequency f of obtaining in the step 1
1(k) with electric power system power frequency f
0(k) compare, construct rational criterion;
Step 3 is carried out transmission line single-phase fault property identification according to the criterion of step 2 structure.
2. the transmission line single-phase fault property identification method based on natural frequency according to claim 1 is characterized in that described step 1 is specifically implemented according to following steps:
Step 1.1, fault phase current i (t) is gathered in transmission line single-phase fault tripping operation back;
Step 1.2 is carried out signal processing such as high-pass filtering to the fault phase current i (t) that collects in the step 1.1;
Step 1.3 is carried out PRONY to the fault phase current i (t) after step 1.2 processing and is analyzed, and extracts the natural frequency dominant frequency frequency f that contains transient state component among the fault phase current i (t) in the PRONY analysis result
1(k).
3. the transmission line single-phase fault property identification method based on natural frequency according to claim 1 is characterized in that, the criterion that makes up in the described step 2 is:
f
1(k)>K
re·f
0(k)；
In above-mentioned criterion, K
ReBe safety factor, K
Re1.
4. the transmission line single-phase fault property identification method based on natural frequency according to claim 1 is characterized in that described step 3 is specifically implemented according to following steps:
After if circuit breaker disconnects, as if the criterion requirement of satisfying in the step 2, can reliably be judged to transmission line single-phase fault character is transient fault;
Otherwise then being judged to transmission line single-phase fault character is permanent fault.
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| CN103616613A (en) * | 2013-11-27 | 2014-03-05 | 武汉大学 | Method for locating fault through travelling wave natural frequencies at two ends of electric transmission line |
| CN104037740A (en) * | 2014-05-31 | 2014-09-10 | 袁芳革 | Arc fault disconnecting device |
| CN106451378A (en) * | 2016-10-28 | 2017-02-22 | 中国人民解放军后勤工程学院 | Identification and judgment method for switching into fault protection |
| CN106972452A (en) * | 2017-04-27 | 2017-07-21 | 西安交通大学 | Utilize the adaptive reclosing method of three-phase of shunt reactor mould power frequency feature |
| CN110474305A (en) * | 2018-05-10 | 2019-11-19 | 中国电力科学研究院有限公司 | A kind of line protection method and device of anti-abnormal electrical data |
| CN110596509A (en) * | 2019-07-09 | 2019-12-20 | 国网江苏省电力有限公司徐州供电分公司 | Power transmission line fault processing system based on different fault types and detection method thereof |
| CN110687477A (en) * | 2019-10-17 | 2020-01-14 | 武汉大学 | Rapid short-circuit fault detection system and method applied to high-voltage substation |
| CN113514727A (en) * | 2021-04-16 | 2021-10-19 | 广东电网有限责任公司电力科学研究院 | Power grid fault arc quenching assessment method, device, equipment and storage medium |
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| CN110474305A (en) * | 2018-05-10 | 2019-11-19 | 中国电力科学研究院有限公司 | A kind of line protection method and device of anti-abnormal electrical data |
| CN110474305B (en) * | 2018-05-10 | 2022-10-04 | 中国电力科学研究院有限公司 | Power transmission line protection method and device for preventing abnormal electrical quantity data |
| CN110596509A (en) * | 2019-07-09 | 2019-12-20 | 国网江苏省电力有限公司徐州供电分公司 | Power transmission line fault processing system based on different fault types and detection method thereof |
| CN110687477A (en) * | 2019-10-17 | 2020-01-14 | 武汉大学 | Rapid short-circuit fault detection system and method applied to high-voltage substation |
| CN113514727A (en) * | 2021-04-16 | 2021-10-19 | 广东电网有限责任公司电力科学研究院 | Power grid fault arc quenching assessment method, device, equipment and storage medium |
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