CN103414150A - Inverse time limit protection method - Google Patents
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Abstract
The invention discloses an inverse time limit protection method which comprises the steps that a microprocessor samples n points from a set inverse time limit characteristic curve, the n points are converted to a weighting coefficient table formed by n weighting coefficients, the weighting coefficient Cx = tx2/tx, wherein tx2 is set fault protection time of a sampling point, tx is fault protection time of the sampling point; the microprocessor sets the fault protection time of the sampling point to be a fault protection threshold value Smax; a detecting device detects a fault parameter Gf in real time, the microprocessor collects the fault parameter Gf detected by the detecting device at intervals of unit time delta t, fault degree Dx is computed; the microprocessor computes a fault influence factor delta S in unit time delta t, delta S = delta t * Cx, the fault influence factor is accumulated, whether S reaches Smax is judged; when S reaches Smax, the microprocessor controls a protection action executive device to carry out protection action. The inverse time limit protection method can be easily achieved on the microprocessor, and fault protection time can be flexibly adjusted.
Description
Technical field
The present invention relates to the load inverse time-lag protection method of device.
Background technology
In a lot of occasions, the reaction time of error protection action is relevant with fault degree, is generally speaking the relation of a kind of inverse time lag, and namely fault degree is larger, and the error protection action is faster.The overcurrent protection in electric power system of take is example, and at present, one second characteristic curve standard of inverse time lag peace has two kinds of IEC255-3 international standard and ANSI Unite States Standards.The IEC255-3 international standard comprises three ampere-second characteristic curves, and the ANSI Unite States Standard comprises four ampere-second characteristic curves.With the extreme inverse-time curve of IEC255-3 for example, its normalized form is as follows:
Wherein, t is operate time, D=I
f/ I
e, I
fThe fault electric current, I
eBe rated current, D is called the overcurrent degree, TMS(Time Multiplier Setting) for the time multiple arranges, select input by the user.
Formula in these standards, owing to relating to complicated exponent arithmetic and floating point arithmetic, is not suitable for realizing on microprocessor.Existing method is that above formula is similar to distortion, in order to realize on microprocessor; Or directly be simplified to the I2t curve, or carry out interpolation fitting by tables of data.
Above these methods, because formula is simplified, inevitably cause error, have affected control precision; Simultaneously, these class methods only offer Protection parameters setting of user usually, and the user is difficult to the inverse time lag is made adjustment; In addition, the versatility of these methods is all not strong, in case change an inverse-time curve, just no longer applicable.
Summary of the invention
Technical problem to be solved by this invention is to provide a kind of load inverse time-lag protection method that is easy to realize, also can adjust neatly the error protection time on microprocessor.
The technical solution adopted in the present invention is: a kind of load inverse time-lag protection method comprises:
Microprocessor n point of anti-time limit characteristic curve sampling to setting, by this anti-time limit characteristic Curve transform, it is the weighting coefficient table formed by n weight coefficient, the corresponding fault degree of each weight coefficient Cx is the sampled point of Dx, wherein, x=1,2 ... ... n, n is more than or equal to 3 integer, Dx=Gf/Ge, Gf is the fault parameter of this sampled point, Ge is rated value, the weight coefficient Cx=of each sampled point sets the error protection time tx of error protection time this sampled point of tx2/ of sampled point, and this setting sampled point is any one sampled point that Dx was greater than 1 o'clock;
The error protection time that microprocessor will be set sampled point is made as error protection threshold value Smax;
The real-time detection failure parameter of checkout gear Gf, the fault parameter Gf that microprocessor detects every a unit interval Δ t collecting and detecting device, and calculate fault degree Dx;
Whether the fault degree Dx that microprocessor judges calculates is greater than 1, if Dx>1 inquire the weight coefficient Cx corresponding with Dx in weighting coefficient table calculates the fault effects factor Δ S of this unit interval Δ t, wherein, Δ S=Δ t*Cx; Simultaneously, microprocessor carries out accumulation calculating to this fault effects factor, and judges whether accumulated value S reaches error protection threshold value Smax;
When accumulated value S reached error protection threshold value Smax, microprocessor was controlled protection action executing device and is carried out the protection action.
Advantage of the present invention is:
1. the present invention, by inverse-time curve being converted to the form be comprised of a plurality of weight coefficients, can realize all kinds of complex curves easily on microprocessor, and is convenient to adjust neatly the error protection time; If adopt mark one to process, can more effectively avoid the complex calculation such as index, floating-point;
2. the present invention has very strong versatility, can be used as all kinds of faults, as protections such as overheated, overvoltages;
3. can setting that carry out the multistage interval be set according to the user.
The accompanying drawing explanation
Fig. 1 is the schematic flow sheet of an embodiment of load inverse time-lag protection method of the present invention.
Fig. 2 shows the anti-time limit characteristic curve of one Application Example according to the present invention.
Fig. 3 shows the inverse time lag weight coefficient curve corresponding with Fig. 2.
Fig. 4 shows the schematic diagram that integral area equates principle.
Fig. 5 is the theory diagram of an embodiment of the implement device of load inverse time-lag protection method of the present invention.
Embodiment
Below in conjunction with accompanying drawing, the present invention is made and further illustrating.
Load inverse time-lag protection method according to an embodiment of the invention comprises the following steps:
Step 1: microprocessor n point of anti-time limit characteristic curve sampling to setting; by this anti-time limit characteristic Curve transform, it is the weighting coefficient table formed by n weight coefficient; the corresponding fault degree of each weight coefficient Cx is the sampled point of Dx; wherein; x=1,2......n; n is more than or equal to 3 integer; Dx=Gf/Ge; Gf is the fault parameter of this sampled point; Ge is rated value; the weight coefficient Cx=of each sampled point sets the error protection time tx of error protection time this sampled point of tx2/ of sampled point, and this setting sampled point can be any one sampled point.The error protection time of each sampled point all can calculate in the normalized form according to this inverse-time curve.Fault parameter Gf herein, rated value Ge, fault degree Dx are all relevant with failure mode, and for example, when failure mode was overcurrent, fault parameter Gf was overcurrent, and rated value Ge is rated current, and fault degree Dx is the overcurrent multiple; When failure mode was overvoltage, fault parameter Gf was overvoltage voltage, and rated value Ge is rated voltage, and fault degree Dx is the overvoltage multiple.
Step 2: the error protection time that microprocessor will be set sampled point is made as error protection threshold value Smax.
Step 3: the real-time detection failure parameter of checkout gear Gf, the fault parameter Gf that microprocessor detects every a unit interval Δ t collecting and detecting device, and calculate fault degree Dx.The order of severity of the big or small representing fault of Dx, Dx≤1 o'clock, protection action executing device is failure to actuate.
Step 4: whether the fault degree Dx that microprocessor judges calculates is greater than 1, if Dx>1 inquire Dx and corresponding weight coefficient Cx in weighting coefficient table calculates the fault effects factor Δ S of this unit interval Δ t, wherein, Δ S=Δ t*Cx; Simultaneously, microprocessor carries out accumulation calculating to this fault effects factor, and judges whether accumulated value S reaches error protection threshold value Smax.At microprocessor, the fault effects factor is carried out in the process of accumulation calculating (not yet reaching error protection threshold value Smax); if Dx is greater than Ds constantly; accumulation calculating can not interrupted; if there is the situation of the fault degree Dx≤Ds calculated, and the duration of Dx≤Ds be greater than the time T of setting
S, accumulated value S is carried out to zero clearing, wherein Ds is the fault degree value of setting, 0≤Ds≤1.The time T of this setting
SCan be constant, or, the time T of this setting
SSize relevant to the size of the fault degree Dx calculated, Dx is larger, Ts is larger.In a single day the size of Ts is determined according to kind and the actual condition of fault, and it can be zero, the situation of Dx≤Ds namely occurs, immediately by the S zero clearing.
More particularly, can adopt following three kinds of modes to exit fault accumulation: mode one, if there is the situation of the fault degree Dx calculated≤1, and the duration of Dx≤1 be greater than the time T of setting
S, direct zero clearing fault accumulated value S; Method two, adopt stagnant ring zero clearing, Ds is made as and is less than certain value of 1, such as duration of Dx≤0.8, be greater than the time T of setting
SAbility zero clearing fault accumulated value S; The thought of method three, employing inverse time lag, Dx is larger, and Ts is larger.Such as will be that 0.8 corresponding Ts is made as 2 seconds with fault degree Dx, and will be that 0.9 corresponding Ts is made as 5 seconds with fault degree Dx.
Step 5: when accumulated value S reached error protection threshold value Smax, microprocessor was controlled protection action executing device and is carried out the protection action.For example, S=Δ S1+ Δ S2+ Δ S3=Δ t*C5+ Δ t*C7+ Δ t*C12, if now S has surpassed Smax, microprocessor is controlled protection action executing device and is carried out the protection action.In a specific embodiment, protection action executing device is for example relay, and the protection action of its described execution is tripping operation.
Step 6: after microprocessor is controlled protection action executing device execution protection action, to the step of accumulated value S zero clearing.
For effectively avoiding the complex calculation such as index, floating-point, in a kind of preferred implementation, in step 1, microprocessor, after by this anti-time limit characteristic Curve transform, being the weighting coefficient table of n weight coefficient composition, carries out the standardization processing to each weight coefficient in weighting coefficient table; And in step 5, microprocessor is after calculating the fault effects factor Δ S of this unit interval Δ t, and S carries out the standardization processing to this Δ.
Fig. 1 shows the schematic flow sheet of above-mentioned steps.
In the time will revising the inverse time protection curve, this load inverse time-lag protection method is further comprising the steps of;
Step 7: to microprocessor input modify instruction; this modify instruction was modified at least to the error protection time of two sampled points on the anti-time limit characteristic curve; the fault degree that one of them sampled point is corresponding is Dx2; the amended error protection time is t ' x2; the fault degree that another sampled point is corresponding is Dx1; the amended error protection time is t ' x1, wherein, and 1<Dx1<Dx2.
Step 8: microprocessor calculates the value of t ' x2/t ' x1, and then in weighting coefficient table, find out the weight coefficient Cx3 approached the most with the value of this t ' x2/t ' x1, the position ordinal number of each weight coefficient Cx in weighting coefficient table means with tp, tp=0,1 ... ... n-1, determine that the position ordinal number tp of this weight coefficient Cx3 in weighting coefficient table equals tp1.
Step 9: microprocessor calculates drawing coefficient hCoff; HCoff=(tp3-tp1)/(tp3-tp2); Wherein, tp3 is the position ordinal number that described one of them sampled point is corresponding, and tp2 is described position ordinal number corresponding to another sampled point that be.
Step 10: microprocessor resets the error protection threshold value, the error protection threshold value S ' max using the error protection time t ' x2 of this one of them sampled point as new settings.
Step 11: the real-time detection failure parameter of checkout gear Gf, the fault parameter Gf that microprocessor detects every a unit interval Δ t collecting and detecting device, and calculate fault degree Dx.
Step 12: microprocessor calculates the position ordinal number tp corresponding with the fault degree Dx calculated in real time according to following formula:
When the fault degree Dx calculated is less than the fault degree Dx2 corresponding with this one of them sampled point, tp=tp '=((Dn-Dx2)-(Dx2-Dx) * hCoff) * n; Wherein, Dn is n fault degree that sampled point is corresponding on the anti-time limit characteristic curve, and its corresponding weight coefficient is Cn;
When the fault degree Dx calculated is more than or equal to this one of them and adopts the corresponding fault degree Dx2 of a point,, tp=tp '=((Dn-Dx2)+(Dx-Dx2) * hCoff) * n.
Step 13: microprocessor rounds processing to the tp ' calculated, weighting coefficient table open find with round after the corresponding weight coefficient Cx of tp '.
Step 14: microprocessor calculates the fault effects factor Δ S ' of this unit interval Δ t, wherein, and Δ S '=Δ t*Cx; Simultaneously, microprocessor carries out accumulation calculating to this fault effects factor, and judges whether accumulated value S ' reaches error protection threshold value S ' max.
Step 15: when accumulated value S ' reached error protection threshold value S ' max, microprocessor was controlled protection action executing device and is carried out the protection action.
Step 16: after microprocessor is controlled protection action executing device execution protection action, to the step of accumulated value S ' zero clearing.
Above-mentionedly tp ' is rounded to processing can adopt following several method:
Method one, make tp=round (tp '), S=∑ Δ S ≈ ∑ (tbl[round (tp')] * Δ t)
Method two, utilize interpolation tp by ceil (tp ') and floor (tp ') acting in conjunction,
S=∑ Δ S ≈ ∑ (tbl[ceil (tp')] * (ceil (tp')-tp')+tbl[floor (tp') * (tp'-floor (tp'))]) * Δ t
Tbl[wherein] be the inverse time lag weighting table, round () is the round function, and ceil () is upper bracket function, and floor () is lower bracket function.
Also can use in addition the methods such as Newton interpolation.
For more effectively avoiding the complex calculation such as index, floating-point, in a kind of preferred implementation, in step 9, after microprocessor calculates drawing coefficient hCoff, this drawing coefficient hCoff is carried out to the standardization processing; And in step 14, microprocessor is after calculating the fault effects factor Δ S ' of this unit interval Δ t, and S ' carries out the standardization processing to this Δ.For example, can be to weighting coefficient table, draw high coefficient h Coff, error protection threshold value S, error protection threshold value S ' amplifies identical multiple simultaneously, as IQ15 commonly used on 512 times or engineering.
Below take the two point form inverse-time overcurrent protection as example illustrates load inverse time-lag protection method of the present invention, the method also can be applied the application scenario (as overvoltage, overheated etc.) of other inverse time protections.The method comprises the following steps:
Step 1: microprocessor 100 points of anti-time limit characteristic curve sampling to setting, the anti-time limit characteristic curve is changed into to the weighting coefficient table tbl[formed by 100 weight coefficients], the anti-time limit characteristic curve of this setting as shown in Figure 2, its normalized form is the formula (1) in background technology, and Fig. 3 shows the inverse time lag weight coefficient curve corresponding with Fig. 2.Weighting coefficient table tbl[] in realizing, the C language shows as an array,, while using in this table element, be aforesaid position ordinal number tp by array index tp() carry out index, as tbl[tp].In addition, press C language syntax subscript tp since 0, i.e. tp=0,1,2 ... 99.Weight coefficient reflects the degree of overcurrent, and the weight coefficient corresponding with these 100 sampled points is respectively C1 to C100.C1, C2, C3 ... C100 is corresponding D1, D2, D3 respectively ... D100, D1, D2, D3 ... D100 is correspondence 1.01,1.02,1.03 respectively ... 2.00 overcurrent degree (because herein fault is overcurrent, so fault degree is the overcurrent degree).This weighting coefficient table is as follows:
tbl[100]={
0.0161,0.0323,0.0487,0.0653,0.0820,0.0989,0.1159,0.1331,0.1505,0.1680,//1.01～1.100.1857,0.2035,0.2215,0.2397,0.2580,0.2765,0.2951,0.3139,0.3329,0.3520,//1.11～1.200.3713,0.3907,0.4103,0.4301,0.4500,0.4701,0.4903,0.5107,0.5313,0.5520,//1.21～1.300.5729,0.5939,0.6151,0.6365,0.6580,0.6797,0.7015,0.7235,0.7457,0.7680,//1.31～1.400.7905,0.8131,0.8359,0.8589,0.8820,0.9053,0.9287,0.9523,0.9761,1.0000,//1.41～1.501.0241,1.0483,1.0727,1.0973,1.1220,1.1469,1.1719,1.1971,1.2225,1.2480,//1.51～1.601.2737,1.2995,1.3255,1.3517,1.3780,1.4045,1.4311,1.4579,1.4849,1.5120,//1.61～1.701.5393,1.5667,1.5943,1.6221,1.6500,1.6781,1.7063,1.7347,1.7633,1.7920,//1.71～1.801.8209,1.8499,1.8791,1.9085,1.9380,1.9677,1.9975,2.0275,2.0577,2.0880,//1.81～1.902.1185,2.1491,2.1799,2.2109,2.2420,2.2733,2.3047,2.3363,2.3681,2.4000;}//1.91～2.00
Here, sampled point that will be corresponding with 1.5 times of overcurrent degree is as setting sampled point, and its corresponding error protection time tx2 can calculate according to formula (1): tx2=64s.So, the error protection time of each sampled point of weight coefficient Cx=64/ of each sampled point.For example, the error protection time of the sampled point corresponding with 1.2 times of overcurrent degree is 181.8s, its weight coefficient C20=0.3520, subscript tp=19.
Step 2: microprocessor calculates error protection threshold value Smax, this error protection threshold value Smax=64s.
Step 3: by current sensing means, detect in real time overcurrent Gf, microprocessor gathers every a unit interval Δ t overcurrent Gf that current sensing means detects, and calculates overcurrent multiple Dx by formula Dx=overcurrent Gf/ rated current Ge.
Step 4: whether the overcurrent multiple Dx that microprocessor judges calculates is greater than 1, if Dx>1 inquire the weight coefficient Cx corresponding with Dx in weighting coefficient table calculates the fault effects factor Δ S of this unit interval Δ t, wherein, Δ S=Δ t*Cx; Simultaneously, microprocessor carries out accumulation calculating to this fault effects factor, and judges whether accumulated value S reaches 64s.
Step 5: when accumulated value S reached 64s, the microprocessor control relay was carried out the tripping operation action.
The principle of above-mentioned error protection is according to the equal principle of integral area.Be about to the weight coefficient Cx corresponding with overcurrent degree Dx and operate time t product be considered as area, as weighing the criterion of whether carrying out error protection, the product of the weight coefficient that each unit interval is corresponding with this section period overcurrent degree is called the fault effects factor; Then in real time the fault effects factor is added up (being integration), as long as this accumulated value exceeds the cumulative protection maximum of setting, just start error protection.If the weight coefficient that overcurrent degree D1 is corresponding obviously is C1 and process t1 time to carry out error protection; if the weight coefficient that overcurrent degree D2 is corresponding is C2 and process t2 time to carry out error protection; can think so C1 * t1=C2 * t2, namely integral area equates that principle carries out error protection.Fig. 4 shows the schematic diagram that integral area equates principle.Fig. 5 is the theory diagram of an embodiment of the implement device of load inverse time-lag protection method of the present invention.Microprocessor 1, checkout gear 2 and protection action executing device 3 have been shown in Fig. 5.
After step 6, microprocessor control relay are carried out the tripping operation action, to accumulated value S zero clearing.
Step 7; to microprocessor input modify instruction; this modify instruction was modified to the error protection time of two corresponding sampled points of inverse-time curve and 1.5 times (are above-mentioned Dx2), 1.2 times of overcurrents (being above-mentioned Dx1); wherein the error protection time modification of 1.5 times of overcurrents is 50s; 1.2 doubly the overcurrent protection time modification is 60s; in this example, x2=50, x1=20.If the multipoint mode overcurrent protection time need to be set; for example, outside 1.2 times, 1.5 times; also need to arrange 1.8 times of overcurrent protection times; can be by [1.0; 1.5] doubly interval as a two point form inverse time lag section, [1.5, ∞) doubly interval as another two point form inverse time lag section; by that analogy, realize the expansion of multipoint mode inverse time lag.
Step 8: microprocessor calculates 50/60=0.8333, and then in weighting coefficient table, finds out and the 0.83 weight coefficient Cx3=0.8359 approached the most, determines its subscript tp=tp1=42 in weighting coefficient table.
Step 9: microprocessor calculates drawing coefficient hCoff; HCoff=(49-42)/(49-19)=7/30; Wherein, 49 is 1.5 times of subscripts that the overcurrent sampled point is corresponding, and 19 is 1.2 times of subscripts that the overcurrent sampled point is corresponding.
Step 10: the error protection time 50s of the sampled point that microprocessor is corresponding using 1.5 times of overcurrents is as error protection threshold value S ' max.
Step 11: by current sensing means, detect in real time overcurrent Gf, microprocessor gathers every a unit interval Δ t overcurrent Gf that current sensing means detects, and calculates overcurrent multiple Dx.
Step 12: microprocessor calculates the position ordinal number tp corresponding with the overcurrent multiple Dx calculated in real time according to following formula:
When the overcurrent multiple Dx calculated is less than 1.5 times, tp=tp '=((2-1.5)-(1.5-Dx) * hCoff) * 100; In this example, during sampled point 100, i.e. n=100, maximum overcurrent multiple Dn is 2 times;
When the fault degree Dx calculated is more than or equal to 1.5 times, tp=tp '=((2-1.5)+(Dx-1.5) * hCoff) * 100.
Step 13: the tp ' that microprocessor calculates rounds processing, weighting coefficient table open find with round after the corresponding weight coefficient Cx of tp ';
Step 14: microprocessor calculates the fault effects factor Δ S ' of this unit interval Δ t, wherein, and Δ S '=Δ t*Cx; Simultaneously, microprocessor carries out accumulation calculating to this fault effects factor, and judges whether accumulated value S ' reaches 50s.
Step 15: when accumulated value S ' reached 50s, the microprocessor control relay was carried out the tripping operation action.
Step 16: after the microprocessor control relay is carried out the tripping operation action, to accumulated value S ' zero clearing.
Claims (7)
1. a load inverse time-lag protection method, is characterized in that, comprising:
Microprocessor n point of anti-time limit characteristic curve sampling to setting, by this anti-time limit characteristic Curve transform, it is the weighting coefficient table formed by n weight coefficient, the corresponding fault degree of each weight coefficient Cx is the sampled point of Dx, wherein, x=1,2 ... ... n, n is more than or equal to 3 integer, Dx=Gf/Ge, Gf is the fault parameter of this sampled point, Ge is rated value, the weight coefficient Cx=of each sampled point sets the error protection time tx of error protection time this sampled point of tx2/ of sampled point, and this sets sampled point is any one sampled point;
The error protection time that microprocessor will be set sampled point is made as error protection threshold value Smax;
The real-time detection failure parameter of checkout gear Gf, the fault parameter Gf that microprocessor detects every a unit interval Δ t collecting and detecting device, and calculate fault degree Dx;
Whether the fault degree Dx that microprocessor judges calculates is greater than 1, if Dx>1 inquire the weight coefficient Cx corresponding with Dx in weighting coefficient table calculates the fault effects factor Δ S of this unit interval Δ t, wherein, Δ S=Δ t*Cx; Simultaneously, microprocessor carries out accumulation calculating to this fault effects factor, and judges whether accumulated value S reaches error protection threshold value Smax;
When accumulated value S reached error protection threshold value Smax, microprocessor was controlled protection action executing device and is carried out the protection action.
2. load inverse time-lag protection method as claimed in claim 1; it is characterized in that; in microprocessor carries out the process of accumulation calculating to the fault effects factor, if there is the situation of the fault degree Dx≤Ds calculated, and the duration of Dx≤Ds be greater than the time T of setting
S, accumulated value S is carried out to zero clearing, wherein Ds is the fault degree value of setting, 0≤Ds≤1.
3. load inverse time-lag protection method as claimed in claim 2, is characterized in that, the time T of this setting
SFor constant.
4. load inverse time-lag protection method as claimed in claim 2, is characterized in that, the time T of this setting
SSize relevant to the size of the fault degree Dx calculated, Dx is larger, Ts is larger.
5. load inverse time-lag protection method as described as any one in claim 1 to 4, it is characterized in that, described microprocessor, after by this anti-time limit characteristic Curve transform, being the weighting coefficient table of n weight coefficient composition, carries out the standardization processing to each weight coefficient in weighting coefficient table;
And microprocessor is after calculating the fault effects factor Δ S of this unit interval Δ t, and S carries out the standardization processing to this Δ.
6. load inverse time-lag protection method as described as any one in claim 1 to 4, is characterized in that, further comprising the steps of;
To microprocessor input modify instruction, this modify instruction was modified at least to the error protection time of two sampled points on the anti-time limit characteristic curve, the fault degree that one of them sampled point is corresponding is Dx2, the amended error protection time is t ' x2, the fault degree that another sampled point is corresponding is Dx1, the amended error protection time is t ' x1, wherein, and 1<Dx1<Dx2;
Microprocessor calculates the value of t ' x2/t ' x1, and then in weighting coefficient table, find out the weight coefficient Cx3 approached the most with the value of this t ' x2/t ' x1, the position ordinal number of each weight coefficient Cx in weighting coefficient table means with tp, tp=0,1 ... ... n-1, determine that the position ordinal number tp of this weight coefficient Cx3 in weighting coefficient table equals tp1;
Microprocessor calculates drawing coefficient hCoff; HCoff=(tp3-tp1)/(tp3-tp2); Wherein, tp3 is the position ordinal number that described one of them sampled point is corresponding, and tp2 is described position ordinal number corresponding to another sampled point that be;
Microprocessor resets the error protection threshold value, the error protection threshold value S ' max using the error protection time t ' x2 of this one of them sampled point as new settings;
The real-time detection failure parameter of checkout gear Gf, the fault parameter Gf that microprocessor detects every a unit interval Δ t collecting and detecting device, and calculate fault degree Dx;
Microprocessor calculates the position ordinal number tp corresponding with the fault degree Dx calculated in real time according to following formula:
When the fault degree Dx calculated is less than the fault degree Dx2 corresponding with this one of them sampled point, tp=tp '=((Dn-Dx2)-(Dx2-Dx) * hCoff) * n;
When the fault degree Dx calculated is more than or equal to the fault degree Dx2 corresponding with this one of them sampled point, tp=tp '=((Dn-Dx2)+(Dx-Dx2) * hCoff) * n;
Microprocessor rounds processing to the tp ' calculated, in weighting coefficient table, find with round after the corresponding weight coefficient Cx of tp ';
Microprocessor calculates the fault effects factor Δ S ' of this unit interval Δ t, wherein, and Δ S '=Δ t*Cx; Simultaneously, microprocessor carries out accumulation calculating to this fault effects factor, and judges whether accumulated value S ' reaches error protection threshold value S ' max;
When accumulated value S ' reached error protection threshold value S ' max, microprocessor was controlled protection action executing device and is carried out the protection action.
7. load inverse time-lag protection method as claimed in claim 6, is characterized in that, described microprocessor, after by this anti-time limit characteristic Curve transform, being the weighting coefficient table of n weight coefficient composition, carries out the standardization processing to each weight coefficient in weighting coefficient table;
Microprocessor is after calculating the fault effects factor Δ S of this unit interval Δ t, and S carries out the standardization processing to this Δ;
After microprocessor calculated drawing coefficient hCoff, hCoff carried out the standardization processing to this drawing coefficient;
And microprocessor is after calculating the fault effects factor Δ S ' of this unit interval Δ t, and S ' carries out the standardization processing to this Δ.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104577957A (en) * | 2015-01-26 | 2015-04-29 | 国家电网公司 | Inverse time limit overcurrent protection method based on FPGA |
| CN105449848A (en) * | 2014-09-29 | 2016-03-30 | 若比邻（天津）科技有限公司 | Fault self-diagnosis and self-recovery power supply system |
| CN107317303A (en) * | 2017-07-31 | 2017-11-03 | 中国航天时代电子公司 | A kind of load current load inverse time-lag protection method |
| CN112505394A (en) * | 2020-11-17 | 2021-03-16 | 北京润科通用技术有限公司 | Overcurrent detection method and device |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1953291A (en) * | 2006-11-22 | 2007-04-25 | 北京四方继保自动化股份有限公司 | A method to realize high precision universal inverse time-limit protection |
| JP2009142136A (en) * | 2007-12-11 | 2009-06-25 | Chugoku Electric Power Co Inc:The | Protective relay with inverse-time element and protecting method of electric power system |
-
2013
- 2013-08-23 CN CN201310374516.8A patent/CN103414150B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1953291A (en) * | 2006-11-22 | 2007-04-25 | 北京四方继保自动化股份有限公司 | A method to realize high precision universal inverse time-limit protection |
| JP2009142136A (en) * | 2007-12-11 | 2009-06-25 | Chugoku Electric Power Co Inc:The | Protective relay with inverse-time element and protecting method of electric power system |
Non-Patent Citations (1)
| Title |
|---|
| 徐厚东等: "微机反时限过流保护算法", 《清华大学学报（自然科学版）》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105449848A (en) * | 2014-09-29 | 2016-03-30 | 若比邻（天津）科技有限公司 | Fault self-diagnosis and self-recovery power supply system |
| CN104577957A (en) * | 2015-01-26 | 2015-04-29 | 国家电网公司 | Inverse time limit overcurrent protection method based on FPGA |
| CN107317303A (en) * | 2017-07-31 | 2017-11-03 | 中国航天时代电子公司 | A kind of load current load inverse time-lag protection method |
| CN107317303B (en) * | 2017-07-31 | 2019-07-09 | 中国航天时代电子公司 | A kind of load current load inverse time-lag protection method |
| CN112505394A (en) * | 2020-11-17 | 2021-03-16 | 北京润科通用技术有限公司 | Overcurrent detection method and device |
| CN112505394B (en) * | 2020-11-17 | 2022-09-20 | 北京润科通用技术有限公司 | Overcurrent detection method and device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103414150B (en) | 2016-08-10 |
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