CN108923392B - Permanent fault recognition-based local feeder fault isolation method and system - Google Patents
Permanent fault recognition-based local feeder fault isolation method and system Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
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Abstract
The invention relates to a permanent fault recognition-based local feeder fault isolation method and system, wherein firstly, when a distribution line has a fault, each section switch on the distribution line is tripped; then, each section switch is subjected to permanent fault judgment, and for any section switch, if the section switch is judged to be a non-permanent fault, the section switch is switched on after time delay, and if the section switch is judged to be a permanent fault, the section switch is not switched on. Therefore, the method only passes through the 'jumping-closing' process once, has the advantage of less switching action times, can avoid permanent fault of switch closing, and has the advantage of small impact on a distribution network system. Moreover, the method does not depend on a communication system, does not need to be matched with a main station, and is simple and reliable in process. In addition, the section switches do not need to be matched step by step, the power supply recovery time of the fault isolation section and the non-fault section is short, and the power supply recovery speed of the fault isolation section and the non-fault section is further accelerated.
Description
Technical Field
The invention relates to a permanent fault identification-based local feeder fault isolation method and system.
Background
Feeder automation is an important function of distribution network automation, and is mainly realized by two ways: a local control mode and a remote control mode. The traditional on-site mode realizes fault isolation and recovery power supply of a non-fault section based on sequential trial-closing of all stages of section switches of a line, and has the defects of more switching action times, long recovery power supply time, multiple fault current impact in permanent fault and the like. The remote control mode is realized by a power distribution automation system, depends on communication, and has the defects of high investment and low reliability. The in-situ feeder automation method based on optical fiber differential protection proposed in recent years still has the disadvantages of dependence on communication and large investment, and in consideration of engineering practice, it is not practical to lay optical fiber channels on all distribution lines.
Chinese patent application publication No. CN105281304A discloses a method for fast feeder fault location and isolation, when a line fails, a protection switch trips, a fault current value is uploaded to a master station and an adjacent intelligent feeder control terminal, a fault section is determined by the master station, then the protection switch is switched on, then reclosing is performed again to perform permanent fault determination, finally section switches on two sides of the fault line are removed and the fault line is isolated, and a healthy line is switched on and restored to supply power by an outgoing line protection switch and a ring network switch of an outgoing line side transformer substation, wherein when the fault line is isolated, the section switches are switched on and off for many times until the fault current disappears. Firstly, the method needs the main station to judge faults, needs to transmit relevant electrical information to the main station, depends on communication, and has the defects of large investment and low reliability, and in the fault isolation process, the section switch needs to carry out multiple reclosing operations, and correspondingly has the defects of multiple switching actions, long power supply recovery time, multiple fault current impact in permanent faults and the like. Therefore, the simple and reliable feeder automation method is found to be of great significance for improving the distribution network automation level.
Disclosure of Invention
The invention aims to provide a permanent fault identification-based local feeder line fault isolation method, which is used for solving the problem that the existing fault isolation method has more switching actions. The invention also provides a local feeder line fault isolation system based on permanent fault identification.
In order to achieve the above object, the present invention includes the following technical solutions.
A permanent fault identification-based local feeder fault isolation method comprises the following steps:
1) when the distribution line has a fault, each section switch on the distribution line is tripped;
2) each section switch carries out permanent fault judgment;
3) for any section switch, if the section switch is judged to be in a non-permanent fault, the section switch is switched on after time delay, and if the section switch is judged to be in a permanent fault, the section switch is not switched on.
When a fault occurs in a distribution line, each section switch on the distribution line is tripped, then each section switch carries out permanent fault judgment, whether any section switch is switched on or not is determined according to a permanent fault identification result, if the section switch is judged to be a non-permanent fault, the section switch is switched on after time delay, and if the section switch is judged to be a permanent fault, the section switch is not switched on. Therefore, the method can realize fault isolation of the line and recovery power supply of the non-fault section only through one tripping and closing process, namely, each section switch only through one tripping and closing action, has the advantages of less switching action times and high recovery power supply speed of the fault isolation and non-fault section, can avoid the switch closing in a permanent fault, prevents multiple short-circuit current impact on a distribution network system, and has the advantage of small impact on the distribution network system. Moreover, the method does not depend on a communication system, does not need to be matched with a main station, and is simple and reliable in process. In addition, the section switches do not need to be matched step by step, the power supply recovery time of the fault isolation section and the non-fault section is short, and the power supply recovery speed of the fault isolation section and the non-fault section is further accelerated. And the permanent fault identification of each line section is independent, the permanent fault identification and the tripping and closing behaviors of the switch are independent, the influence of the grid structure and the line type is avoided, the application range is wide, and the method is suitable for distribution lines with various grid structures and types.
Further, the non-permanent fault refers to no fault or a transient fault.
Further, the permanent fault discrimination includes a permanent fault discrimination strategy for an asymmetric interphase short-circuit fault of the fault type and/or a permanent fault discrimination strategy for a three-phase short-circuit fault of the fault type that is symmetric:
the permanent fault discrimination strategy aiming at the asymmetric interphase short circuit fault with the fault type comprises the following steps:
(1) firstly, short-circuiting an interphase loop of any fault phase and a normal phase, and then putting capacitors into the interphase loops corresponding to the two phases with faults;
(2) detecting three-phase current after the capacitor is put into operation, comparing the intermediate value and the minimum value in the three-phase current, and judging that permanent faults occur if the intermediate value is larger than the minimum value of the set multiple;
the permanent fault discrimination strategy for the three-phase short-circuit fault with the symmetrical fault type comprises the following steps:
(1) when the fault occurs, the two corresponding phase-to-phase loops with the minimum line voltage are put into the capacitor;
(2) and detecting three-phase current after the capacitor is put into operation, comparing the maximum current in the three-phase current with a set current threshold, and judging that a permanent fault occurs if the maximum current is greater than the set current threshold.
For the asymmetric interphase short-circuit fault, before reclosing action, according to the phase selection result of the fault, firstly, the interphase loop of any fault phase and the normal phase is short-circuited, then, the capacitor is put into the interphase loop corresponding to the two phases with the fault, according to the transient characteristics of three-phase current after the capacitor is put into the interphase loop, namely, the intermediate value and the minimum value in the three-phase current are compared, and whether the line fault is permanent or not is identified according to the magnitude relation between the intermediate value and the minimum value of the set multiple. For a three-phase short-circuit fault with a symmetrical fault type, before reclosing action, a capacitor is put into an interphase loop corresponding to any two phases according to a phase selection result of the fault, the maximum current in the three-phase current is compared with a set current threshold according to the transient characteristics of the three-phase current after the capacitor is put into the interphase loop, and whether the line fault is permanent or not is identified according to the magnitude relation between the maximum current and the set current threshold. The permanent fault judgment method only relates to the capacitor and the on-off control switch thereof, in addition, other equipment is not needed to be added, the method is simple in process, the relation among three-phase currents is analyzed to judge whether the fault line fault is permanent or not after the capacitor is put into the circuit, complex operation is not needed, and a complex equation is not needed to be established. The operation process is simple, the reliability is high when the corresponding software program is implemented, the burden of the control system is light when the corresponding software program is executed, the control system does not need to bear heavy operation burden, and the requirement on the hardware of the control system is low.
An in-place feeder fault isolation system based on permanent fault identification comprises a distribution line, wherein at least two section switches are arranged on the distribution line; the system implements the following fault isolation strategy:
1) when the distribution line has a fault, each section switch on the distribution line is tripped;
2) each section switch carries out permanent fault judgment;
3) for any section switch, if the section switch is judged to be in a non-permanent fault, the section switch is switched on after time delay, and if the section switch is judged to be in a permanent fault, the section switch is not switched on.
Furthermore, each section switch is provided with a power distribution terminal for judging permanent faults, and the permanent faults at the corresponding section switches are judged.
Further, the non-permanent fault refers to no fault or a transient fault.
Further, the permanent fault discrimination includes a permanent fault discrimination strategy for an asymmetric interphase short-circuit fault of the fault type and/or a permanent fault discrimination strategy for a three-phase short-circuit fault of the fault type that is symmetric:
the permanent fault discrimination strategy aiming at the asymmetric interphase short circuit fault with the fault type comprises the following steps:
(1) firstly, short-circuiting an interphase loop of any fault phase and a normal phase, and then putting capacitors into the interphase loops corresponding to the two phases with faults;
(2) detecting three-phase current after the capacitor is put into operation, comparing the intermediate value and the minimum value in the three-phase current, and judging that permanent faults occur if the intermediate value is larger than the minimum value of the set multiple;
the permanent fault discrimination strategy for the three-phase short-circuit fault with the symmetrical fault type comprises the following steps:
(1) when the fault occurs, the two corresponding phase-to-phase loops with the minimum line voltage are put into the capacitor;
(2) and detecting three-phase current after the capacitor is put into operation, comparing the maximum current in the three-phase current with a set current threshold, and judging that a permanent fault occurs if the maximum current is greater than the set current threshold.
Drawings
Fig. 1 is an equivalent circuit diagram of a non-permanent fault corresponding to an asymmetric interphase short-circuit fault;
FIG. 2 is an equivalent circuit diagram of a permanent fault corresponding to an asymmetric interphase short-circuit fault;
FIG. 3 is an equivalent circuit diagram of a symmetrical three-phase short circuit fault corresponding to a non-permanent fault;
FIG. 4 is an equivalent circuit diagram of a permanent fault corresponding to a symmetrical three-phase short circuit fault;
figure 5 is a diagram of a double-ended power distribution line;
FIG. 6 is a schematic diagram of the operation mode after feeder automation action in the case of a k-point transient fault;
fig. 7 is a schematic diagram of the operation mode after the feeder automation action when the k point is in permanent failure.
Detailed Description
Method embodiment
The embodiment provides a permanent fault identification-based local feeder fault isolation method, which comprises the following steps:
1) when the distribution line has a fault, each section switch on the distribution line is tripped;
2) before each section switch is switched on, permanent fault discrimination is carried out on each section switch which is switched off, and under the general condition, permanent fault discrimination is carried out after fault detection delay;
3) and (4) performing closing control according to the permanent fault identification result, wherein a power distribution terminal or equipment for judging the permanent fault is required to be arranged at each section switch. Then, for any section switch, if the section switch is determined as a non-permanent fault (here, the non-permanent fault refers to no fault or a transient fault), that is, the power distribution terminal at the section switch is determined as the non-permanent fault, the section switch is turned on after a delay, and a specific delay time is set according to an actual situation, but of course, the delay time may also be zero; and if the section switch is judged to have a permanent fault, the section switch is closed in a locking mode and is not closed any more.
The present embodiment provides a permanent failure determination method, and specifically, as follows, it is needless to say that other conventional determination methods may be adopted.
The permanent fault determination mode comprises a permanent fault determination strategy aiming at the asymmetrical interphase short-circuit fault of the fault type and/or a permanent fault determination strategy aiming at the symmetrical three-phase short-circuit fault of the fault type. Therefore, the permanent fault determination method may include any one of a permanent fault determination policy for an asymmetric interphase short-circuit fault as the fault type and a permanent fault determination policy for a symmetric three-phase short-circuit fault as the fault type, or may include both of them at the same time, and this embodiment takes the example of including both of them at the same time.
The permanent fault discrimination strategy aiming at the asymmetric interphase short circuit fault with the fault type comprises the following steps: (1) firstly, short-circuiting an interphase loop of any fault phase and a normal phase, and then putting capacitors into the interphase loops corresponding to the two failed phases, namely setting the AB interphase, the BC interphase and the CA interphase, wherein the fault phase is a first interphase, the sequence is a second interphase and a third interphase, and the first interphase is connected with two ends of the capacitors; the second phase and the third phase have two processing modes: the first phase and the second phase are in short connection, and the third phase is not in wiring; the second phase and the second phase are not connected, and the third phase is short-circuited; (2) detecting capacitor input back three-phase current (here, capacitor input point and alternate short circuit point are located between switch and CT, through CT detection capacitor input back three-phase current), then, according to three-phase current transient state characteristic identification fault characteristics: and comparing the intermediate value Imid and the minimum value Imin in the three-phase current by adopting a relative principle, judging that a permanent fault occurs if the intermediate value is greater than the minimum value of a set multiple (i.e. Imid > k Imin, wherein k is a set asymmetric coefficient and is generally 3-10), and otherwise, judging that an instantaneous fault occurs or no fault occurs. In the above, among the AB phase, BC phase, and CA phase, the failure phase is the first phase, the second phase and the third phase in the following order, and therefore, the first phase, the second phase, and the third phase do not have unique correspondence relationships with the AB phase, BC phase, and CA phase.
The permanent fault discrimination strategy aiming at the three-phase short-circuit fault with the symmetrical fault type comprises the following steps: 1) when the fault occurs, the two corresponding phase-to-phase loops with the minimum line voltage are put into the capacitor; 2) detecting three-phase current after the capacitor is put into operation, wherein the detection mode is the same as the upper section, and then identifying fault characteristics according to the transient characteristics of the three-phase current: and comparing the maximum current Imax in the three-phase current with a set current threshold Iset by adopting absolute judgment, judging that the line has a permanent fault if the maximum current Imax is greater than the set current threshold Iset (namely Imax is greater than Iset), and judging that the line has an instantaneous fault or no fault if the maximum current Imax is greater than the set current threshold Iset.
In the two strategies, the capacitor is charged.
Of course, before implementing the permanent fault determination method, the fault type needs to be determined first, and since the failure type determination method belongs to the conventional technology and is not related to the protection point of the present invention, the details are not described here, for example: and judging the fault type according to the negative sequence voltage, judging as an asymmetric interphase short-circuit fault and selecting two phases with smaller line voltage as fault phases if the negative sequence voltage U2 is greater than a set value (such as 6V) during line fault, otherwise, judging as a symmetric three-phase short-circuit fault.
A specific example of each of the above two strategies is given below.
Aiming at the asymmetric interphase short circuit fault of the fault type:
the asymmetric interphase short-circuit fault is exemplified by an AB interphase fault. Then, the two phases that fail are the a phase and the B phase, and the C phase is the normal phase. Then, in the above, the first phase is the AB phase, the second phase is the BC phase, and the third phase is the CA phase. The interphase loop short-circuiting any fault phase and normal phase (i.e. any non-fault interphase loop) is the interphase loop short-circuiting phase A and phase C or the interphase loop short-circuiting phase B and phase C, and the capacitor is put into the interphase loop corresponding to the two failed phases (i.e. the fault interphase loop), i.e. the capacitor is put into the interphase loops of phase A and phase B, as shown in fig. 1 or 2.
The three-phase current characteristics at permanent faults are analyzed with an AB phase-to-phase fault by means of fig. 1 and 2 as follows:
as shown in fig. 1, when a non-permanent fault occurs in a line, the fault circuit is insulated and recovered, and the capacitor is discharged from phase a to phase BC through the load resistance, and the impedance of the three-phase circuit is approximately symmetrical, so that the following characteristics are provided: IB-IC-0.5 IA, i.e.: the middle phase current value and the minimum phase current value in the three-phase current are basically equal.
As shown in fig. 2, when a permanent fault occurs in the line, the fault point transition impedance is set as Z, Z is much smaller than the load impedance Zfh, and the capacitor discharges from phase a to phase BC through the load impedance Zfh and the fault point transition impedance Z, at which time the three-phase loop impedance is no longer symmetrical, and the following characteristics are provided: IB is much larger than IC because IA1 is much larger than IA2 because the transition impedance Z is much smaller than the load impedance Zfh, IB is much larger than IC, IB is equal to IA1+0.5IA2, and IC is equal to 0.5IA 2. Namely: the middle phase current value in the three-phase current is far larger than the minimum phase current value.
Thus, a permanent fault identification criterion can be constructed: and sequencing IA, IB and IC to respectively obtain a maximum value Imax, a middle value Imid and a minimum value Imin, and if the intermediate value is far larger than the minimum value when the Imid is larger than k and Imin is satisfied, judging the fault as a permanent fault, wherein k is an asymmetric threshold value and is generally 3-10.
Aiming at the three-phase short-circuit fault with the symmetrical fault type:
when the fault is a symmetrical three-phase short-circuit fault, two corresponding phase-to-phase loops with the lowest line voltage at the fault are thrown into a capacitor, such as: and if the interphase voltage of the A phase and the B phase is minimum, putting a capacitor into an interphase loop of the A phase and the B phase. That is, among the phases AB, BC, and CA, the fault phase with the lowest line voltage at the time of the fault is the first phase, the second phase, and finally the third phase, and then the first phase connects both ends of the capacitor, and the second phase and the third phase are not connected. Of course, the correspondence relationship between the first phase, the second phase, and the third phase and the AB phase, the BC phase, and the CA phase is not unique.
As shown in fig. 3, when a non-permanent fault occurs in the line, the capacitor discharge loop impedance is the sum of the load impedance and the line impedance. As shown in fig. 4, when a permanent fault occurs in the line, the impedance of the capacitor discharge circuit is only the line impedance from the head end of the line to the point of fault. It can be seen that the impedance of the capacitor discharge circuit at the time of the permanent fault is much smaller than that at the time of the transient fault, that is, the capacitor discharge current at the time of the permanent fault is much larger than that at the time of the transient fault.
Therefore, a permanent fault identification criterion can be constructed: and setting a current constant value (namely a current threshold value) Iset, finding out the maximum phase current Imax in the three phase currents, and judging as a permanent fault when the maximum phase current Imax is greater than Iset.
In addition, the fault detection delay of each section switch needs to avoid the insulation recovery time of a fault point when a line has a transient fault, and each section switch does not need to be matched step by step, so that the fault isolation and non-fault section recovery power supply speed is high.
System embodiment
The embodiment provides a local feeder line fault isolation system based on permanent fault identification, which comprises a distribution line, wherein at least two section switches are arranged on the distribution line, and the system realizes fault isolation according to a local feeder line fault isolation method based on permanent fault identification, so that the protection point of the system still lies in the local feeder line fault isolation method based on permanent fault identification.
And each section switch is provided with a power distribution terminal for realizing permanent fault judgment of the corresponding section switch. A specific implementation of the power distribution terminal is described in detail in the above method embodiments, and will not be described in detail here. In addition, the power distribution terminal also has the functions of fault opening and reclosing. Therefore, each section switch corresponds to the relevant control, such as: the opening control, the permanent fault judgment and the reclosing operation are all realized by corresponding power distribution terminals.
The method of on-site feeder fault isolation based on permanent fault identification is described below in connection with a specific double-ended power distribution line.
As shown in fig. 5, the double-ended power distribution line is a double-ended power supply line, wherein the position of Q5-1 is an open-loop point, Q5-1 is an open-loop switch, Q1 and Q7 are circuit breakers corresponding to double-ended power supplies, and other switches are section switches.
When a fault occurs at a certain position in the distribution line, for example, when a short-circuit fault occurs at the point k, the breaker at the position Q1 is tripped, and the section switches at the positions Q2-1, Q2-2, Q3-1, Q3-2, Q4-1 and Q4-2 feel no voltage and then are tripped sequentially. Because the distribution line is supplied with power from both ends, normally, the open-loop switch Q5-1 is in the open state. When a short-circuit fault occurs at point k, the line at the end corresponding to the breaker Q7 is not affected.
After fault detection delay of each sectional switch, each switch carries out fault property identification, wherein, for the distribution line of the double-end power supply, the open-loop switch Q5-1 also carries out permanent fault detection. If a transient fault occurs at the position k, the identification results of Q1, Q2-1, Q2-2, Q3-1, Q3-2, Q4-1, Q4-2 and Q5-1 are non-permanent faults; if a permanent fault occurs at the position k, the results of the identification of Q1, Q2-1, Q2-2, Q3-1, Q4-2 and Q5-1 are non-permanent faults, and the results of the identification of Q3-2 and Q4-1 are permanent faults.
Then, after the closing delay, the corresponding switch with the non-permanent fault property identification result is closed. The method specifically comprises the following steps: when a transient fault occurs at the position k, the switches at the positions Q1, Q2-1, Q2-2, Q3-1, Q3-2, Q4-1, Q4-2 and Q5-1 are switched on, and as shown in figure 6, the line returns to normal. When a permanent fault occurs at the position k, the switches at the positions Q1, Q2-1, Q2-2, Q3-1, Q4-2 and Q5-1 are closed, and the switches at the positions Q3-2 and Q4-1 are kept in an opening state, as shown in figure 7.
The specific embodiments are given above, but the present invention is not limited to the described embodiments. The basic idea of the present invention lies in the above basic scheme, and it is obvious to those skilled in the art that no creative effort is needed to design various modified models, formulas and parameters according to the teaching of the present invention. Variations, modifications, substitutions and alterations may be made to the embodiments without departing from the principles and spirit of the invention, and still fall within the scope of the invention.
Claims (4)
1. A permanent fault identification-based local feeder fault isolation method is characterized by comprising the following steps:
1) when the distribution line has a fault, each section switch on the distribution line is tripped;
2) each section switch carries out permanent fault judgment;
3) for any section switch, if the section switch is judged to be a non-permanent fault, the section switch is switched on after time delay, and if the section switch is judged to be a permanent fault, the section switch is not switched on again;
the permanent fault discrimination comprises a permanent fault discrimination strategy aiming at the asymmetrical interphase short-circuit fault of the fault type and/or a permanent fault discrimination strategy aiming at the symmetrical three-phase short-circuit fault of the fault type:
the permanent fault discrimination strategy aiming at the asymmetric interphase short circuit fault with the fault type comprises the following steps:
(1) firstly, short-circuiting an interphase loop of any fault phase and a normal phase, and then putting capacitors into the interphase loops corresponding to the two phases with faults;
(2) detecting three-phase current after the capacitor is put into operation, comparing the intermediate value and the minimum value in the three-phase current, and judging that permanent faults occur if the intermediate value is larger than the minimum value of the set multiple;
the permanent fault discrimination strategy for the three-phase short-circuit fault with the symmetrical fault type comprises the following steps:
(1) when the fault occurs, the two corresponding phase-to-phase loops with the minimum line voltage are put into the capacitor;
(2) and detecting three-phase current after the capacitor is put into operation, comparing the maximum current in the three-phase current with a set current threshold, and judging that a permanent fault occurs if the maximum current is greater than the set current threshold.
2. A method of on-site feeder fault isolation based on permanent fault identification as claimed in claim 1 wherein the non-permanent fault is a no fault or a transient fault.
3. An in-place feeder fault isolation system based on permanent fault identification is characterized by comprising a distribution line, wherein at least two section switches are arranged on the distribution line; the system implements the following fault isolation strategy:
1) when the distribution line has a fault, each section switch on the distribution line is tripped;
2) each section switch carries out permanent fault judgment;
3) for any section switch, if the section switch is judged to be a non-permanent fault, the section switch is switched on after time delay, and if the section switch is judged to be a permanent fault, the section switch is not switched on again; each section switch is provided with a power distribution terminal for judging permanent faults, so that the permanent faults at the corresponding section switches are judged;
the permanent fault discrimination comprises a permanent fault discrimination strategy aiming at the asymmetrical interphase short-circuit fault of the fault type and/or a permanent fault discrimination strategy aiming at the symmetrical three-phase short-circuit fault of the fault type:
the permanent fault discrimination strategy aiming at the asymmetric interphase short circuit fault with the fault type comprises the following steps:
(1) firstly, short-circuiting an interphase loop of any fault phase and a normal phase, and then putting capacitors into the interphase loops corresponding to the two phases with faults;
(2) detecting three-phase current after the capacitor is put into operation, comparing the intermediate value and the minimum value in the three-phase current, and judging that permanent faults occur if the intermediate value is larger than the minimum value of the set multiple;
the permanent fault discrimination strategy for the three-phase short-circuit fault with the symmetrical fault type comprises the following steps:
(1) when the fault occurs, the two corresponding phase-to-phase loops with the minimum line voltage are put into the capacitor;
(2) and detecting three-phase current after the capacitor is put into operation, comparing the maximum current in the three-phase current with a set current threshold, and judging that a permanent fault occurs if the maximum current is greater than the set current threshold.
4. A permanent fault identification based in-situ feeder fault isolation system as claimed in claim 3, wherein the non-permanent fault is a no fault or a transient fault.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202435023U (en) * | 2012-02-14 | 2012-09-12 | 广州南方电力集团电器有限公司 | Novel intelligent controller of outdoor pole-mounted switch |
| CN105281304A (en) * | 2015-12-02 | 2016-01-27 | 国网上海市电力公司 | Quick feeder fault positioning and isolating method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN202435023U (en) * | 2012-02-14 | 2012-09-12 | 广州南方电力集团电器有限公司 | Novel intelligent controller of outdoor pole-mounted switch |
| CN105281304A (en) * | 2015-12-02 | 2016-01-27 | 国网上海市电力公司 | Quick feeder fault positioning and isolating method |
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