CN104852368A - Line differential protection method based on differential output of electronic current transformer - Google Patents
Line differential protection method based on differential output of electronic current transformer Download PDFInfo
- Publication number
- CN104852368A CN104852368A CN201510272251.XA CN201510272251A CN104852368A CN 104852368 A CN104852368 A CN 104852368A CN 201510272251 A CN201510272251 A CN 201510272251A CN 104852368 A CN104852368 A CN 104852368A
- Authority
- CN
- China
- Prior art keywords
- differential
- current
- line
- protection
- current transformer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 20
- 230000010354 integration Effects 0.000 claims abstract description 10
- 230000005540 biological transmission Effects 0.000 claims abstract description 8
- 230000009471 action Effects 0.000 claims description 21
- 238000004422 calculation algorithm Methods 0.000 claims description 7
- 210000003127 knee Anatomy 0.000 claims description 6
- 230000009466 transformation Effects 0.000 claims description 4
- 238000004088 simulation Methods 0.000 abstract description 8
- 230000002411 adverse Effects 0.000 abstract description 4
- 230000000694 effects Effects 0.000 abstract description 4
- 101100499229 Mus musculus Dhrsx gene Proteins 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 11
- 238000005070 sampling Methods 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- 230000003044 adaptive effect Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000005350 ferromagnetic resonance Effects 0.000 description 2
- VYMDGNCVAMGZFE-UHFFFAOYSA-N phenylbutazonum Chemical compound O=C1C(CCCC)C(=O)N(C=2C=CC=CC=2)N1C1=CC=CC=C1 VYMDGNCVAMGZFE-UHFFFAOYSA-N 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 2
- RZVAJINKPMORJF-UHFFFAOYSA-N Acetaminophen Chemical compound CC(=O)NC1=CC=C(O)C=C1 RZVAJINKPMORJF-UHFFFAOYSA-N 0.000 description 1
- 238000012952 Resampling Methods 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000003302 ferromagnetic material Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000012782 phase change material Substances 0.000 description 1
- 230000010363 phase shift Effects 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000004445 quantitative analysis Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Landscapes
- Emergency Protection Circuit Devices (AREA)
Abstract
The invention provides a line differential protection method based on differential output of an electronic current transformer, and belongs to the field of power system relay protection. The technical scheme is that an integration element in high-voltage side data processing of conventional line differential protection is removed, and differential signals output by the sensing head of a Rogowski coil are directly used to realize longitudinal differential protection of a high-tension transmission line, and complexity of a device is reduced, and data processing time is reduced. On the basis of ensuring reliability and speed, adverse effect caused by an extra integral circuit is prevented, the method adapts to differential output of the Rogowski coil. PSCAD/EMTDC simulation experiments show that the differential protection scheme based on the current differential signals is effective and feasible, line rapid differential protection can be realized by directly using the differential signals output by the electronic current transformer, the integration element is removed. The method adapts to requirements of interfaces of the electronic current transformer, and can be used for main protection of high-tension transmission lines.
Description
Technical Field
The invention discloses a differential output line differential protection method based on an electronic current transformer, and belongs to the field of relay protection of power systems.
Background
With the development of the power industry, the required power transmission capacity is continuously increased, and the operating voltage level is higher and higher. The traditional electromagnetic mutual inductor has inherent problems of iron core saturation, remanence, ferromagnetic resonance and the like, and is more and more difficult to meet the increasingly developed requirements of power systems. The electronic transformer is applied to thoroughly solve the problems, has all functions of the traditional transformer, has the advantages of no influence of saturation and ferromagnetic resonance, good insulating property, wide frequency band, large dynamic range, small volume, light weight, suitability for digital protection development and the like, and has the characteristics of greatly improving the relay protection performance undoubtedly.
In recent years, electronic current transformers based on Rogowski coils have been put into practical use, but since the output signal of the sensing head is the differential of the measured current, an additional integration module is required to restore the original signal, which will increase the data processing time of the high-voltage side, cause a certain time delay and phase shift, further limit the operation speed of protection, reduce reliability, and increase the energy supply burden of the high-voltage side.
Disclosure of Invention
The invention provides a method for realizing rapid differential protection of a line by applying a differential signal output by an electronic current transformer, which fully utilizes effective information directly output by a sensing head, reduces the complexity of a device, reduces the data processing time, avoids adverse effects brought by an integral link, is favorable for rapid action of differential protection, does not need to transmit time information for synchronous processing by virtue of a channel, does not need to calculate channel time delay, meets the requirements of IEC61850-9-2 standard, is adaptive to differential output of a Rogowski coil, and solves the problems in the prior art.
In order to achieve the purpose, the invention adopts the following technical scheme:
a differential output line differential protection method based on an electronic current transformer comprises the following steps:
step 1: the method includes the steps that a high-voltage side data acquisition system of an electronic current transformer installed at two ends of a power transmission line in a protection mode is used for directly acquiring a current differential signal output by a Rogowski coil sensing head of the electronic current transformerAnd：
wherein、the actual measured currents (primary values) at the M and N terminals of the line respectively,、the differential signals (secondary values) of the measuring current output by the sensing heads of the electronic current transformers at the M end and the N end of the line respectively,is the transformation ratio coefficient of the electronic current transformer,tis time;
step 2: using full-wave Fourier algorithm to solveAndphasor value of corresponding fundamental wave componentAnd，、and、amplitude-phase relationship of (1):
wherein、are respectively in step 1、The phasor value of the corresponding fundamental component,、are respectively in step 1、The amplitude of the corresponding fundamental component is,、are respectively in step 1、The phase angle of the corresponding fundamental component,is the angular frequency of the fundamental wave,；
and step 3: determining differential currentAnd differential braking current，、And、the relationship of (1):
，wherein、the differential current and the brake current of the traditional line differential protection added with an integration module are respectively,、、、、has the same meaning as in step 2;
and 4, step 4: the differential current obtained in step 3And differential braking currentSubstituting the action equation:
when the action condition of the action equation is met, tripping is protected, otherwise, the protection does not act; wherein,for the knee current of the line differential protection of the conventional add-on integration block,for the starting current of the traditional line differential protection incorporating an integrating module,Kin order to be the slope of the braking line,、、the meaning of (3) is the same as that of step 3.
The invention provides a novel method for realizing line differential protection by directly utilizing differential output of an electronic current transformer, which has the following basic principle:
(1) differential output signal based on Rogowski coil ECT
The equivalent circuit of the Rogowski coil is shown in figure 1,R 0is the internal resistance of the coil and,Lis the self-inductance coefficient of the coil,R Lis a load resistance, and is,Cis the inter-turn capacitance of the coil,e(t) Is the induced potential of the coil. The induced electromotive force of the coil satisfies the following formula:
（1）
wherein,Mis the mutual inductance of the coil,iis the measured current.
The Rogowski coil equivalent circuit shown in fig. 1 can be given by the formula:
（2）
the input and output relationship obtained by taking Laplace transform and simplifying is as follows:
（3）
when in useAnd is andwhen the Rogowski coil is in open-circuit working state, the Rogowski coil is in open-circuit working stateThe inverse Laplace transformation is as follows:
（4）
the output voltage is proportional to the differential of the measured current with respect to time, which is the outer integral operating state of the Rogowski coil ECT. In practical application, the outer integration working mode can realize the measurement of pulse current, power frequency current and harmonic current, and is the main working mode of the Rogowski coil ECT.
(2) Basic principle of current longitudinal differential protection
As shown in fig. 2, which is a basic schematic diagram of the conventional pilot current differential protection, when the line MN operates normally and the protected line is short-circuited (k 2), currents on both sides are equal in magnitude and opposite in direction, and phasor and modulus are approximately zero; when the line is short-circuited (k 1), the fault current flowing through both sides of the line is positive, and the phasor and modulus are large. Differential relay (KD) rootAccording to the phasor sum of the secondary currents on both sides) And judging whether the intra-area fault occurs according to the magnitude of the modulus value.
(3) Full wave fourier algorithm
When the power system is in fault, the obtained current is a periodic function, and besides the fundamental component, the current also contains various harmonics and non-attenuated direct current components. It is not provided that this function is set toThe Fourier series is as follows:
（5）
in the formula、Amplitudes of sine phase and cosine phase of direct current, fundamental wave and each harmonic component respectively,is the angular frequency of the fundamental wave,in order to be the harmonic frequency, the frequency of the harmonic wave,represented as a direct current component. According to the principle of Fourier series, the whole-cycle Fourier algorithm can be obtained:
（6）
whereinTIs the fundamental period, thereforeThe subharmonic component of (a) is:
（7）
（8）
when implemented on a computer, such algorithms perform calculations on discrete sample values. Calculated by discrete valuesAndfor the value of (c), the two integrals can be obtained by the trapezoidal rule:
（9）
in the formulaNThe number of sampling points for one period is,is as followskA sample value. The algorithm uses all samples of a cycle to make the calculation, so that the length of the data window is one sample periodT. It can be seen that if only can、Find out the currentnAmplitude of subharmonic componentInitial phase angleCan be calculated. When in usenIf =1, the calculation result is the amplitude and phase angle of the current fundamental component.
The invention has the beneficial effects that: the invention provides a novel method for realizing line differential protection by utilizing differential output signals of an electronic current transformer. The method makes full use of effective information output by a sensing head of the electronic current transformer, reduces the complexity of the device, reduces the data processing time, and avoids adverse effects caused by an additional integrating circuit on the basis of ensuring the reliability and the speed. In addition, the differential signal output by the electronic current transformer is directly used for realizing the rapid differential protection of the line, the integral link is removed, the requirement of the interface of the electronic current transformer is met, and the differential protection circuit has wide application prospect and can be used as the main protection of a high-voltage transmission line.
Drawings
Fig. 1 is an equivalent schematic diagram based on a Rogowski coil ECT;
FIG. 2 is a schematic diagram of a conventional pilot current differential protection;
FIG. 3 is a comparison of the present invention and conventional differential protection ratio braking characteristics;
FIG. 4 is a diagram of a differential protection scheme for a line based on differential output of a Rogowski coil;
FIG. 5 is a diagram of a differential protection simulation model based on current differential signals;
FIG. 6 is a time series diagram of differential and braking current modulus values during an intra-zone fault on a line;
FIG. 7 is a time series diagram of differential and braking current modulus values when an out-of-band fault occurs on a line;
FIG. 8 is a graph of differential protection ratio braking characteristics based on current differential signals when an in-zone fault occurs in a line;
FIG. 9 is a graph of differential protection ratio braking characteristics based on current differential signals when an out-of-range fault occurs on the line;
fig. 10 is a flow chart of a line differential protection method based on differential output of an electronic current transformer.
Detailed Description
The invention will be further explained with reference to the drawings.
A differential output line differential protection method based on an electronic current transformer comprises the following implementation steps:
step 1: the method includes the steps that a high-voltage side data acquisition system of an electronic current transformer installed at two ends of a power transmission line in a protection mode is used for directly acquiring a current differential signal output by a Rogowski coil sensing head of the electronic current transformerAnd：
wherein、the actual measured currents (primary values) at the M and N terminals of the line respectively,、the differential signals (secondary values) of the measuring current output by the sensing heads of the electronic current transformers at the M end and the N end of the line respectively,is the transformation ratio coefficient of the electronic current transformer,tis time;
step 2: using full-wave Fourier algorithm to solveAndphasor value of corresponding fundamental wave componentAnd，、and、amplitude-phase relationship of (1):
wherein、are respectively in step 1、The phasor value of the corresponding fundamental component,、are respectively in step 1、The amplitude of the corresponding fundamental component is,、are respectively in step 1、The phase angle of the corresponding fundamental component,is the angular frequency of the fundamental wave,；
and step 3: determining differential currentAnd differential braking current，、And、the relationship of (1):
，wherein、the differential current and the brake current of the traditional line differential protection added with an integration module are respectively,、、、、has the same meaning as in step 2;
and 4, step 4: the differential current obtained in step 3And differential braking currentSubstituting the action equation:
when the action condition of the action equation is met, tripping is protected, otherwise, the protection does not act; wherein,for the knee current of the line differential protection of the conventional add-on integration block,for the starting current of the traditional line differential protection incorporating an integrating module,Kin order to be the slope of the braking line,、、the meaning of (3) is the same as that of step 3.
Fig. 2 is a basic schematic diagram of the pilot current differential protection. When the line MN normally operates and the protected line is externally short-circuited (k 2), currents on two sides are equal in magnitude and opposite in direction, and phasor and modulus are approximately zero; when the line is short-circuited (k 1), the fault current flowing through both sides of the line is positive, and the phasor and modulus are large. The differential relay (KD) judges whether the zone fault occurs according to the phasor and the magnitude of the modulus of the secondary current on the two sides.
From the equation (4), the output signal of the Rogowski coil sensing head is the differential of the measured current, and therefore, a differential protection scheme based on the differential output principle of the electronic current transformer is designed.
The instantaneous value of the current at two ends of the line is not set as:
（10）
wherein,I m 、I n is the effective value of the fundamental current at two ends of the line,is the angular frequency of the fundamental wave,、is an initial phase angle of the phase-change material,tis time.
The corresponding current phasors are:
（11）
the differential of the primary current is:
（12）
the corresponding current phasors are:
(13)
in the same way, the following can be obtained:
(14)
further, the differential current can be obtained as:
(15)
from the equation (15), the differential protection operation current modulus based on the differential current becomes the original oneAnd (4) doubling.
In order to increase the sensitivity in the case of an internal short circuit and the reliability of the failure in the case of an external short circuit, differential relays with braking properties are often used.
The domestic protection usually adopts phasor difference braking current:
(16-a)
(16-b)
in the formula (16-a),、current phasor and braking quantity at two ends of lineIs the modulus of the current phasor difference on both sides. In the formula (16-b),for the phasor difference braking current based on the differential output of the electronic current transformer,it is of a sizeAnd (4) doubling.
The action equation of the ratio brake type differential protection based on the current differential signal is derived as follows:
(17)
in the formula:in order to differentiate the differential current flow,in order to differentiate the braking current, the braking current is,in order to differentiate the knee current,in order to differentiate the start-up current,Kis the brake line slope.
A differential protection ratio braking characteristic curve based on the differential signal can be plotted according to equation (17) as shown in fig. 3.
Fig. 1 is an equivalent circuit diagram of a Rogowski coil.R 0Is the internal resistance of the coil and,Lis the self-inductance coefficient of the coil,R Lis a load resistance, and is,Cis the inter-turn capacitance of the coil,e(t) Is the induced potential of the coil or coils,U ois the output voltage. The Rogowski coil is usually manufactured by uniformly winding an enameled wire on an annular framework, the framework is made of non-ferromagnetic materials such as plastics or ceramics, the relative permeability of the framework is the same as that of air, and the phenomenon of iron core saturation cannot occur, which is a remarkable characteristic different from the traditional current transformer with an iron core.
Fig. 2 is a basic schematic diagram of a conventional pilot current differential protection, in which when a line MN is in normal operation and an external short circuit (k 2) of a protected line occurs, currents on two sides are equal in magnitude and opposite in direction, and phasor and modulus values are approximately zero; when the line is short-circuited (k 1), the fault current flowing through both sides of the line is positive, and the phasor and modulus are large. Wherein,、respectively line two-side protection deviceThe phasor value of the primary current is measured,、respectively protecting the phase value of the secondary current at the installation position at two sides of the circuit, and the differential relay (KD) is based on the sum of the phase values of the secondary currents at two sidesAnd judging whether the intra-area fault occurs according to the magnitude of the modulus value.
FIG. 3 is a comparison graph of the braking characteristic curves of the new and old differential protection ratios. Wherein,in order to be a differential current flow,in order to brake the current, the brake current is,in the form of a knee-point current,in order to initiate the flow of current,in order to differentiate the differential current flow,in order to differentiate the braking current, the braking current is,in order to differentiate the knee current,is the differential starting current.
Fig. 4 shows a differential protection scheme for a circuit based on differential output of a Rogowski coil, which comprises a Rogowski coil sensing head, a high-voltage side data acquisition system, an optical fiber transmission and interface, a merging unit, a clock synchronization module, a protection module, a power supply module and the like.
After being filtered by an anti-aliasing filter, a differential signal output by the Rogowski coil is not subjected to integral reduction, synchronous sampling is directly performed through an A/D module, an analog differential signal is converted into a digital signal, and finally the digital signal is converted into an optical signal through E/O conversion and then transmitted to a low-voltage side for use by a protection device. On the low-voltage side, the merging unit receives the sampling signals after O/E conversion, and after the sampling signals are processed by modules such as resampling and phase compensation, the sampling signals are encoded and output according to the IEC61850-9-2 format. Meanwhile, the merging unit transmits the received GPS second pulse signal and the time signal to the A/D sampling module on the high-voltage side in an uplink mode. The current differential signal processed by the merging unit is transmitted to a protection device through a process layer switch, so that a rapid differential protection scheme based on differential output of the electronic current transformer is realized.
FIG. 5 shows a differential protection simulation model based on current differential signals, which is built based on a PSCAD/EMTDC platform. The rated voltage of a power supply is 500kV, the rated power is 300MVA, and the frequency is 50 Hz; the line model adopts a Bergeron distributed parameter model, the total length of the line is 300km, and the parameters are as follows:z 1=0.035+j0.42Ω/km ，z 0=0.30+ j1.14 Ω/km. The simulation total time is 0.5s, the fault starting time is 0.22s, and the fault duration is 0.1 s. In the simulation process, the current data obtained at two ends of the line are processed by a differential module in PSCAD to simulate the differential output of the Rogowski coil.
Fig. 6 and 7 show differential and braking current module value time sequence diagrams when a line has an intra-area fault and an extra-area fault, wherein the intra-area fault is an A-phase grounding short circuit at a position 100km away from an M-end bus, and the extra-area fault is an A-phase grounding short circuit at an outlet of the M-end bus. The solid line represents a differential current, and the broken line represents a differential brake current.
As can be seen from fig. 6, the differential current mode value is much larger than the differential braking current mode value when the zone is short-circuited, the protection can give a trip command within a half period and has high sensitivity; it can be seen from fig. 7 that the differential braking current is greatly increased when the short circuit occurs outside the area, and the differential current is reduced, because the line voltage is reduced when the short circuit occurs outside the area, the line capacitance current is greatly reduced compared with the line capacitance current when the short circuit does not occur, the fault currents flowing through the two-end protection are almost equal in magnitude and opposite in direction, the phasor difference braking current is very small, and the protection is reliable and does not act.
Fig. 8 and 9 show differential protection ratio braking characteristic curves based on current differential signals corresponding to fig. 6 and 7. During simulation, the braking current is the braking current with phase difference and the braking coefficientKTake 0.5, differential starting currentDifferential knee current。
As can be easily seen from fig. 8 and 9, when an intra-zone fault occurs, the differential protection based on the current differential signal operates reliably, and the operation time mainly depends on the magnitude of the differential starting current value; when the fault is out of the area, the differential braking-differential curve is always in the non-action area of the ratio braking characteristic curve, so that the protection is reliable and does not act.
For further quantitative analysis, the simulation results are summarized in tables 1 to 3. In tables 1 to 3, except for the variables in each table, the other parameters are default values: 1) a metallic short circuit; 2) the A phase is grounded and short-circuited at a position 100km away from the M end bus; 3) the phase angle difference of the power supplies at the two ends is 20 degrees; 4) the braking current is the phase difference braking current. The action quantity and the brake quantity in each table are measured to obtain a module value after a fault period so as to be convenient for comparison. In order to increase the reliability of the protection action, a holding time of 4ms is taken, namely, the protection action trips after the differential and the braking current meet the condition of an action equation and are held for 4 ms.
Table 1 shows the differential protection operation based on the current differential signal under different transition resistance conditions. When the zone is in fault, the action quantity is rapidly reduced along with the increase of the transition resistance, the braking quantity is not greatly changed, and the action time of protection is prolonged. This is because the value of the fault component current at both ends of the line becomes smaller as the fault point transition resistance increases, so that the magnitude of the differential current becomes smaller than the load current for a longer time than the starting current value set in a certain proportion to the load current, resulting in an increase in the protection operation time.
Table 2 shows the differential protection operation under different fault location conditions. The action time of protection is not changed greatly and is about 7-9 ms. This is because when short circuits occur at different positions in the area, the phase relationship changes little although the ratio of the amplitudes of the measured currents at the two ends of the line changes. When the motion amount is reduced, the braking amount is correspondingly reduced, so that the time domain range in which the motion amount is larger than the braking amount after the fault has little influence.
Table 3 shows the differential protection operation under different phase angle difference conditions of the two-terminal power supplies. Along with the increase of the voltage difference of the power supplies at the two ends, the action quantity is reduced, the differential quantity is increased, the action time is slightly increased, and the change rule accords with the action principle of differential protection.
The simulation results show that the differential protection scheme based on the current differential signal meets the requirement of a high-voltage line on a relay protection device, is adaptive to the differential output of a Rogowski coil sensing head, avoids adverse effects caused by adding an integrating circuit, and is effective and feasible.
Fig. 10 is a flow chart of a line differential protection method based on differential output of an electronic current transformer.
Claims (1)
1. A differential output line differential protection method based on an electronic current transformer is characterized by comprising the following steps:
step 1: the method includes the steps that a high-voltage side data acquisition system of an electronic current transformer installed at two ends of a power transmission line in a protection mode is used for directly acquiring a current differential signal output by a Rogowski coil sensing head of the electronic current transformerAnd：
wherein、the actual measured currents (primary values) at the M and N terminals of the line respectively,、the differential signals (secondary values) of the measuring current output by the sensing heads of the electronic current transformers at the M end and the N end of the line respectively,is the transformation ratio coefficient of the electronic current transformer,tis time;
step 2: using full-wave Fourier algorithm to solveAndphasor value of corresponding fundamental wave componentAnd，、and、amplitude-phase relationship of (1):
wherein、are respectively in step 1、The phasor value of the corresponding fundamental component,、are respectively in step 1、The amplitude of the corresponding fundamental component is,、are respectively in step 1、The phase angle of the corresponding fundamental component,is the angular frequency of the fundamental wave,；
and step 3: determining differential currentAnd differential braking current，、And、the relationship of (1):
，wherein、the differential current and the brake current of the traditional line differential protection added with an integration module are respectively,、、、、has the same meaning as in step 2;
and 4, step 4: the differential current obtained in step 3And differential braking currentSubstituting the action equation:
when full ofTripping is protected under the action condition of the foot action equation, otherwise, the protection does not act; wherein,for the knee current of the line differential protection of the conventional add-on integration block,for the starting current of the traditional line differential protection incorporating an integrating module,Kin order to be the slope of the braking line,、、the meaning of (3) is the same as that of step 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510272251.XA CN104852368A (en) | 2015-05-26 | 2015-05-26 | Line differential protection method based on differential output of electronic current transformer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510272251.XA CN104852368A (en) | 2015-05-26 | 2015-05-26 | Line differential protection method based on differential output of electronic current transformer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104852368A true CN104852368A (en) | 2015-08-19 |
Family
ID=53851808
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510272251.XA Pending CN104852368A (en) | 2015-05-26 | 2015-05-26 | Line differential protection method based on differential output of electronic current transformer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104852368A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106026049A (en) * | 2016-07-25 | 2016-10-12 | 国网山东省电力公司聊城供电公司 | Differential protection device based on optical current transformer |
| CN106058804A (en) * | 2016-07-25 | 2016-10-26 | 国网山东省电力公司聊城供电公司 | Optical current transformer based line total current differential protection judging method |
| CN106356822A (en) * | 2016-10-10 | 2017-01-25 | 许继集团有限公司 | Underreach combined type protection method and device for semi-wavelength power transmission line |
| CN110146780A (en) * | 2019-04-24 | 2019-08-20 | 国网江苏省电力有限公司电力科学研究院 | Isolated neutral flexibility distribution network system ferromagnetic resonance method of discrimination |
| CN111987698A (en) * | 2020-07-30 | 2020-11-24 | 许继集团有限公司 | Differential current differential protection method for different types of current transformer mixed lines |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101800415A (en) * | 2010-04-27 | 2010-08-11 | 宁夏回族自治区电力公司 | Longitudinal differential protection method of electric furnace transformer |
| CN103887779A (en) * | 2014-04-04 | 2014-06-25 | 国家电网公司 | Transfer trip method of power transmission line |
-
2015
- 2015-05-26 CN CN201510272251.XA patent/CN104852368A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101800415A (en) * | 2010-04-27 | 2010-08-11 | 宁夏回族自治区电力公司 | Longitudinal differential protection method of electric furnace transformer |
| CN103887779A (en) * | 2014-04-04 | 2014-06-25 | 国家电网公司 | Transfer trip method of power transmission line |
Non-Patent Citations (1)
| Title |
|---|
| 高广玲: ""电子式电流互感器传变特性及适应性保护原理研究"", 《中国博士学位论文全文数据库》 * |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106026049A (en) * | 2016-07-25 | 2016-10-12 | 国网山东省电力公司聊城供电公司 | Differential protection device based on optical current transformer |
| CN106058804A (en) * | 2016-07-25 | 2016-10-26 | 国网山东省电力公司聊城供电公司 | Optical current transformer based line total current differential protection judging method |
| CN106026049B (en) * | 2016-07-25 | 2018-10-16 | 国网山东省电力公司聊城供电公司 | Differential protection based on optical current mutual inductor |
| CN106356822A (en) * | 2016-10-10 | 2017-01-25 | 许继集团有限公司 | Underreach combined type protection method and device for semi-wavelength power transmission line |
| CN106356822B (en) * | 2016-10-10 | 2019-02-05 | 许继集团有限公司 | A kind of deficient range combinations formula guard method of half-wave power transmission route and device |
| CN110146780A (en) * | 2019-04-24 | 2019-08-20 | 国网江苏省电力有限公司电力科学研究院 | Isolated neutral flexibility distribution network system ferromagnetic resonance method of discrimination |
| CN110146780B (en) * | 2019-04-24 | 2021-06-08 | 国网江苏省电力有限公司电力科学研究院 | Ferromagnetic resonance distinguishing method for neutral point ungrounded flexible power distribution network system |
| CN111987698A (en) * | 2020-07-30 | 2020-11-24 | 许继集团有限公司 | Differential current differential protection method for different types of current transformer mixed lines |
| WO2022022751A1 (en) * | 2020-07-30 | 2022-02-03 | 许继集团有限公司 | Differential method for current differential protection for line having mixed use of different types of current transformers |
| CN111987698B (en) * | 2020-07-30 | 2022-10-04 | 许继集团有限公司 | Differential current differential protection method for different types of current transformer mixed lines |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ribeiro et al. | Power systems signal processing for smart grids | |
| CN104852368A (en) | Line differential protection method based on differential output of electronic current transformer | |
| CN103226176B (en) | A kind of wire selection method for power distribution network single phase earthing failure | |
| CN100576677C (en) | High-credibility excitation inrush current braking method of transformer device | |
| CN103604991B (en) | The busbar voltage phase measurement device of capacitance type potential transformer and method | |
| CN103235172B (en) | Current measuring method and measuring device | |
| CN108318762B (en) | Method for judging power frequency ferromagnetic resonance of voltage transformer | |
| CN101105517A (en) | Gamma/ transformer triangle winding circumfluence algorithm method and device | |
| CN102129000A (en) | Converter transformer protection RTDS real-time digital closed loop test system for and method thereof | |
| CN102879671B (en) | Method for judging inrush current locking of equivalent instantaneous inductance for protection of extra-high voltage regulating transformer | |
| CN103323698A (en) | Novel current transformer saturation identification method | |
| He et al. | Performance analysis and threshold quantization of transformer differential protection under sampled value packets loss/delay | |
| CN103532113A (en) | Rapid distance protection method for power transmission line containing micro-grid system | |
| CN110146780B (en) | Ferromagnetic resonance distinguishing method for neutral point ungrounded flexible power distribution network system | |
| CN103795030B (en) | A kind of connect the transformer relay protecting method of conductance based on vertical propping up | |
| Xia et al. | Enhanced transmission line pilot impedance and pilot protection | |
| CN110048372B (en) | Improved high-voltage generator stator single-phase earth fault protection method | |
| Wannous et al. | The impact of current transformer saturation on the distance protection | |
| CN105957696B (en) | Current transformer for DC resistance measurement and preparation method thereof | |
| Li et al. | An improved fast distance relay to mitigate the impacts of Rogowski coil transducer transient | |
| Popov et al. | Increase of sensitivity of current longitudinal differential protection of intersystem power lines | |
| Li et al. | Harmonic distortion feature of AC transformers caused by DC bias | |
| CN201974488U (en) | RTDS (real-time digital simulator) real-time digital closed-loop converter transformer protection test system | |
| CN109709429A (en) | Wind power system ferromagnetic resonance analysis method and device | |
| CN107664710B (en) | Multiphase current and voltage crosstalk correction method for power system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| EXSB | Decision made by sipo to initiate substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20150819 |