CN110957709A - Line break protection method for comparing line voltage vector difference at two sides of line and matching with spare power automatic switching - Google Patents

Line break protection method for comparing line voltage vector difference at two sides of line and matching with spare power automatic switching Download PDF

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Publication number
CN110957709A
CN110957709A CN201911247180.2A CN201911247180A CN110957709A CN 110957709 A CN110957709 A CN 110957709A CN 201911247180 A CN201911247180 A CN 201911247180A CN 110957709 A CN110957709 A CN 110957709A
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line
power supply
power
line voltage
bus
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CN110957709B (en
Inventor
刘昶
胡浩
孙东杰
杨静
马骏毅
朱燕妮
朱文韬
姜正驰
汤勋
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State Grid Jiangsu Electric Power Co Ltd Zhenjiang Power Supply Branch
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State Grid Jiangsu Electric Power Co Ltd Zhenjiang Power Supply Branch
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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
    • H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
    • H02H7/261—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations
    • H02H7/262—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations involving transmissions of switching or blocking orders
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
    • H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/30—Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S20/00—Management or operation of end-user stationary applications or the last stages of power distribution; Controlling, monitoring or operating thereof
    • Y04S20/20—End-user application control systems

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  • Emergency Management (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The invention discloses a disconnection protection method for comparing line voltage vector differences at two sides of a line with the matching of backup power automatic switching. The invention adopts a relay protection scheme that the voltage information at two sides of the line is transmitted through the optical fiber channel of the line, the line voltage amplitude difference at two sides of the line is compared to identify the line break, the circuit breaker at the power supply side of the line is tripped or the circuit breaker at the load side is tripped, then the substation spare power automatic switching action at the load side is used for starting the circuit breaker at the trip incoming line and closing the circuit breaker at the spare power supply, so that the transformer losing the power supply is recovered to the power supply on the spare power supply, thereby effectively preventing the influence of the phase-lacking power supply of the transformer on the power grid and.

Description

Line break protection method for comparing line voltage vector difference at two sides of line and matching with spare power automatic switching
Technical Field
The invention relates to a disconnection protection method for comparing line voltage vector difference on two sides of a line and matching with a spare power automatic switch, and belongs to the technical field of protection and control of a power transmission and distribution network.
Background
At present, the line disconnection phenomenon of 3-66 kV (including 3, 6, 10, 20, 35 and 66kV) lines occurs in power grids in various places, and the line disconnection causes the phase-loss operation of a transformer supplied by the lines, so that the three-phase voltage of the transformer is asymmetric, the influence is generated on load power supply, electrical equipment can be damaged, for example, a motor is damaged due to the phase-loss operation. In the prior art, no relay protection device and method specially aiming at the disconnection of a 3-66 kV line exist. The invention provides a single-phase disconnection relay protection method which transmits voltage information of two sides of a line through a line optical fiber channel at a load end transformer substation, compares line voltage vector differences of the two sides of the line to identify disconnection of a 3-66 kV line, trips a power supply side circuit breaker or a load side circuit breaker of the line to be disconnected, and recovers power supply through a spare power automatic switch of the load end 3-66 kV transformer substation.
Disclosure of Invention
The invention aims to provide a disconnection protection method for comparing line voltage vector differences on two sides of a line with a spare power automatic switching device, which is used for a load end 3-66 kV transformer substation, transmits voltage information on two sides of the line through a line optical fiber channel, compares the line voltage vector differences on the two sides of the line to identify line disconnection, trips a power supply side circuit breaker or a load side circuit breaker of the disconnected line, and recovers power supply through the spare power automatic switching device of the load end 3-66 kV transformer substation.
The purpose of the invention is realized by the following technical scheme:
a disconnection protection method for comparing line voltage vector difference on two sides of a line with spare power automatic switching comprises the following steps:
judging the condition of line power supply side breaker or load side breaker and recovering power supply by spare power automatic switch
1.1, judging a power supply side circuit breaker 4DL or a load side circuit breaker 1DL of a No. 1 circuit disconnection jump No. 1 disconnection circuit and a standby power supply circuit breaker 2DL or 3DL started by a load side backup automatic switch, and starting a No. 1 circuit disconnection alarm condition:
collecting secondary AB line voltage of power supply side bus PT
Figure BDA0002307881300000011
BC line voltage
Figure BDA0002307881300000012
CA line voltage
Figure BDA0002307881300000013
Load end I section bus PT secondary AB line voltage of transformer substation
Figure BDA0002307881300000014
BC line voltage
Figure BDA0002307881300000015
CA line voltage
Figure BDA0002307881300000016
Conditions are as follows: (1) no. 1 line power supply side bus PT secondary AB line voltage vector
Figure BDA0002307881300000017
And load end I section bus PT secondary AB line voltage vector of transformer substation
Figure BDA0002307881300000018
Absolute value of vector difference, power supply side bus PT secondary BC line voltage vector
Figure BDA0002307881300000019
And load end I section bus PT secondary BC line voltage vector of transformer substation
Figure BDA00023078813000000110
Absolute value of vector difference, power supply side bus PT secondary CA line voltage vector
Figure BDA00023078813000000111
And load end transformer substation I section bus PT secondary CA line voltage vector
Figure BDA00023078813000000112
The absolute value of the vector difference of (1), two of the absolute values of the three vector differences being 0.519EabTo 0.953EabOne is less than or equal to 0.1Eab；EabThe rated line voltage value of the power supply;
(2) power supply end corresponding bus PT secondary AB line voltage value UA1B1Greater than or equal to 0.9Eab1.1E or lessab；
(3) Power supply end corresponding bus PT secondary BC line voltage value UB1C1Greater than or equal to 0.9Eab1.1E or lessab；
(4) Power supply end corresponding bus PT secondary CA line voltage value UC1A1Greater than or equal to 0.9Eab1.1E or lessab；
(5) The power end 35kV line breaker 4DL of the No. 1 line is at the switching-on position;
(6) the load end 35kV line breaker 1DL of the No. 1 line is at the switching-on position;
if all the conditions are met, identifying and judging that the No. 1 power line is broken, carrying out broken line protection in the line protection of a superior substation, and tripping a No. 1 power line power supply side circuit breaker 4 DL; as the No. 1 power line loses power, the load end substation spare power automatic switching action starts to trip off the No. 1 power incoming line breaker 1DL, closes the spare power breaker 2DL or 3DL, or the disconnection protection in the No. 1 line protection of the load end substation trips the No. 1 power line load side breaker 1 DL; as the No. 1 power supply circuit loses power supply, the load end transformer substation is in standby automatic switching action, and the standby power supply circuit breaker 2DL or 3DL is started to be closed, so that the transformer losing the power supply is recovered to the standby power supply circuit for supplying power; simultaneously starting No. 1 line disconnection alarm;
1.2 judging No. 2 line disconnection jumping No. 2 disconnection line power supply side circuit breaker 5DL or load side circuit breaker 2DL and load side backup power supply circuit breaker 1DL or 3DL started by load side backup automatic switch, and starting No. 2 line disconnection alarm conditions:
collecting secondary AB line voltage of power supply side bus PT
Figure BDA0002307881300000021
BC line voltage
Figure BDA0002307881300000022
CA line voltage
Figure BDA0002307881300000023
Load end I section bus PT secondary AB line voltage of transformer substation
Figure BDA0002307881300000024
BC line voltage
Figure BDA0002307881300000025
CA line voltage
Figure BDA0002307881300000026
Conditions are as follows: (1) no. 2 line power supply side bus PT secondary AB line voltage vector
Figure BDA0002307881300000027
And load end I section bus PT secondary AB line voltage vector of transformer substation
Figure BDA0002307881300000028
Absolute value of vector difference, power supply side bus PT secondary BC line voltage vector
Figure BDA0002307881300000029
And load end I section bus PT secondary BC line voltage vector of transformer substation
Figure BDA00023078813000000210
Absolute value of vector difference, power supply side bus PT secondary CA line voltage vector
Figure BDA00023078813000000211
And load end transformer substation I section bus PT secondary CA line voltage vector
Figure BDA00023078813000000212
The absolute value of the vector difference of (1), two of the absolute values of the three vector differences being 0.519EabTo 0.953EabOne is less than or equal to 0.1Eab；EabThe rated line voltage value of the power supply;
(2) power supply end corresponding bus PT secondary AB line voltage value UA1B1Greater than or equal to 0.9Eab1.1E or lessab；
(3) Power supply end corresponding bus PT secondary BC line voltage value UB1C1Greater than or equal to 0.9Eab1.1E or lessab；
(4) Power supply end corresponding bus PT secondary CA line voltage value UC1A1Greater than or equal to 0.9Eab1.1E or lessab；
(5) The power supply end circuit breaker 5DL of the No. 2 circuit is at the switching-on position;
(6) the load side line breaker 2DL of line No. 2 is in the on position;
if the conditions are all met, identifying and judging that the No. 2 power line is broken, carrying out broken line protection in the line protection of a superior substation, and tripping a No. 2 power line power supply side circuit breaker 5 DL; as the No. 2 power supply line loses power supply, the load end substation is in standby automatic switching action, the No. 2 power supply incoming line breaker 2DL is started to be tripped, the standby power supply breaker 1DL or 3DL is closed, or the line break protection in the No. 2 line protection of the load end substation is used for tripping the No. 2 power supply line load side breaker 2 DL; as the No. 2 power supply circuit loses power supply, the load end transformer substation is in standby automatic switching action, and the standby power supply circuit breaker 1DL or 3DL is started to be closed, so that the transformer losing the power supply is recovered to the standby power supply circuit for supplying power; and simultaneously, starting No. 2 line disconnection alarm.
The object of the invention can be further achieved by the following technical measures:
the disconnection protection method for comparing the line voltage vector difference at two sides of the line and matching with the spare power automatic switching is applied to a mode that a neutral point of a transformer is not grounded or is grounded through an arc suppression coil and a low-resistance grounding system.
The method for protecting the disconnection of the line by comparing the vector difference of the line voltages at the two sides of the line and the matching of the spare power automatic switching is characterized in that the rated line voltage value E of the secondary side of the PTabIs 100V.
According to the line break protection method for comparing the line voltage vector difference of the two sides of the line with the matching of the backup power automatic switching, t1 is 0.1-0.2 second when three phases are not in phase when the breaker is switched on.
Compared with the prior art, the invention has the beneficial effects that:
1. the method fully utilizes the fault characteristics of the secondary voltage of the power supply end and the load end substation bus PT during the single-phase line break of the line, compares the line voltage vector differences of the buses at the two ends of the line, identifies the line single-phase line break and line jump power side circuit breaker or load side circuit breaker, and is simple and easy to implement.
2. The invention adopts a relay protection scheme that the voltage information at two sides of the line is transmitted through the optical fiber channel of the line, the line voltage amplitude difference at two sides of the line is compared to identify the line break, the circuit breaker at the power supply side of the line is tripped or the circuit breaker at the load side is tripped, then the substation spare power automatic switching action at the load side is used for starting the circuit breaker at the trip incoming line and closing the circuit breaker at the spare power supply, so that the transformer losing the power supply is recovered to the power supply on the spare power supply, thereby effectively preventing the influence of the phase-lacking power supply of the transformer on the power grid and.
3. The method of the invention is implemented by adopting the line protection devices at two sides of the line, and does not need to increase hardware equipment.
Drawings
FIG. 1 is a schematic diagram of a primary system of a superior substation with 35kV side not grounded or grounded through an arc suppression coil;
FIG. 2 is a vector diagram of the voltage of a 35kV bus on the power supply side without grounding or through arc suppression coils;
FIG. 3 is a vector diagram of the voltage of a 35kV bus on the load side without grounding or through an arc suppression coil;
FIG. 4 is a schematic diagram of a primary system with a 35kV line break and a load side line break grounded;
FIG. 5 is a vector diagram of the voltage of a 35kV bus on the load side at a load side disconnection point;
FIG. 6 is a schematic diagram of a primary system with a 35kV line broken and a power supply side grounded;
FIG. 7 is a vector diagram of the voltage of a 35kV bus at the ground power supply side at a power supply side disconnection;
FIG. 8 is a vector diagram of the voltage of a 35kV bus at the grounded load side at the power supply side disconnection;
fig. 9 is a schematic diagram of a primary system of a superior substation with 35kV side grounded through a resistor;
FIG. 10 is a vector diagram of 35kV bus voltage at the 35kV side of the upper-level substation via the resistance grounding power supply side;
fig. 11 is a voltage vector diagram of a 35kV bus at a 35kV side of an upper-level substation through a resistance grounding load side;
FIG. 12 is a schematic diagram of a primary system with a 35kV line break and a load side line break grounded;
FIG. 13 is a vector diagram of the voltage of a 35kV bus at the load side which is grounded at a load side disconnection;
FIG. 14 is a schematic diagram of a 35kV primary system with a power supply side disconnected and a ground connection;
FIG. 15 is a schematic diagram of the disconnection protection of the present invention;
FIG. 16 is a primary main wiring diagram of a single bus segment of a 35kV substation;
FIG. 17 is a primary main wiring diagram of an inner bridge of a 35kV substation;
FIG. 18 is a primary main wiring diagram of an enlarged inner bridge of a 35kV substation;
fig. 19 is a primary main connection of a 35kV line transformer set of a 35kV substation.
Detailed Description
The invention is further described with reference to the following figures and specific examples.
Firstly, analyzing fault characteristics by taking 35kV line breakage as an example:
1.1 ungrounded or arc-suppression coil grounding system
1.1.135 kV line broken wire
Fig. 1 is a schematic diagram of a 35kV primary disconnection system, taking an a-phase stub as an example. The 35kV side of the upper-level transformer substation is not grounded or is grounded through an arc suppression coil, and the 35kV neutral point of the 35kV transformer substation on the load side is not grounded. The power supply potentials at 35kV sides of the upper-level transformer substation are respectively set as EA、EB、EC，UNAnd if α line breaks are set for the 35kV neutral point voltage of the transformer substation on the power supply side, the capacitance to ground of the bus side of the transformer substation from the line break position to the upper level is α C, and the capacitance to ground of the bus of the transformer substation from the line break position to the load side is (1- α) C.
1. Power supply side bus voltage analysis
Analyzing to obtain the voltage of a bus at the 35kV side of the upper-level transformer substation as follows:
Figure BDA0002307881300000041
(1) in the formula (I), the compound is shown in the specification,
Figure BDA0002307881300000042
the voltage of a power side 35kV bus A1B1 line, the voltage of a B1C1 line and the voltage of a C1A1 line are respectively. ,
Figure BDA0002307881300000043
the method is characterized in that the voltage of power supply lines at 35kV side of a superior substation is equal in size, a voltage vector diagram of 35kV bus at the power supply side is shown in figure 2, as can be seen from figure 2, when the line A of a 35kV line is disconnected, the voltage of three-phase line of the 35kV bus at the superior substation is constant and keeps symmetrical, α in the diagram is changed between 0 and 1, and 0 point is shown as 0 in figure 2α＝0To 0α＝1When α is equal to 1, point 0 is at 0α＝1At point, when α is 0, 0 is at 0α＝0(the same applies below).
2. Load side bus voltage analysis
The 35kV load side bus voltage is analyzed as follows:
Figure BDA0002307881300000051
(2) in the formula (I), the compound is shown in the specification,
Figure BDA0002307881300000052
the line voltage of the load side 35kV bus A2B2, the line voltage of B2C2 and the line voltage of C2A2 are shown in a vector diagram of the load side 35kV bus in figure 3.
As can be seen from FIG. 3, when the 35kV line is disconnected, the load side
Figure BDA0002307881300000053
Is composed of
Figure BDA0002307881300000054
Is equal to
Figure BDA0002307881300000055
1.1.235 kV line disconnection and load side disconnection grounding
Fig. 4 is a schematic diagram of a 35kV line break and load side line break grounding primary system, taking an a-phase stub as an example. The 35kV side of the upper-level transformer substation is not grounded, and the 35kV neutral point of the 35kV transformer substation on the load side is not grounded. The power supply potentials at 35kV sides of the upper-level transformer substation are respectively set as EA、EB、EC，UNThe capacitance to ground of the 35kV bus of the transformer substation from the broken line to the upper-level substation is α C, and the capacitance to ground of the 35kV bus of the transformer substation from the broken line to the load side is (1- α) C.
1. Power supply side bus voltage analysis
The analysis was as in 1.1.1.
2. Load side bus voltage analysis
The 35kV load side bus voltage is analyzed as follows:
Figure BDA0002307881300000056
the vector diagram of the 35kV bus voltage on the load side is shown in figure 5.
As can be seen from FIG. 5, when the 35kV line is broken and the load side broken line is grounded,
Figure BDA0002307881300000057
is equal to
Figure BDA0002307881300000058
α varies between 0 and 1 according to the distance of the broken line close to the power supply side bus bar, and simultaneously
Figure BDA0002307881300000059
In that
Figure BDA00023078813000000510
To a change of 0, point 0 being as in FIG. 5 0α＝0To 0α＝1The number of the intermediate change is changed,
Figure BDA00023078813000000511
in that
Figure BDA00023078813000000512
To
Figure BDA00023078813000000513
While varying between
Figure BDA00023078813000000514
In that
Figure BDA00023078813000000515
To
Figure BDA00023078813000000516
And (4) change.
1.1.335 kV line disconnection and power supply side disconnection point grounding
Fig. 6 is a schematic diagram of a primary system with a 35kV line broken and a power supply side grounded, taking an a-phase short line as an example. The 35kV side of the upper-level transformer substation is not grounded, and the 35kV neutral point of the 35kV transformer substation on the load side is not grounded. The power supply potentials at 35kV sides of the upper-level transformer substation are respectively set as EA、EB、EC，UNThe capacitance to ground of the 35kV bus of the transformer substation from the broken line to the upper-level substation is α C, and the capacitance to ground of the 35kV bus of the transformer substation from the broken line to the load side is (1- α) C.
1. Power supply side bus voltage analysis
Analyzing the voltage of a bus at the 35kV side of the upper-level transformer substation:
Figure BDA0002307881300000061
the vector diagram of the 35kV bus voltage at the power supply side is shown in figure 7.
As can be seen from fig. 7, when the 35kV line is disconnected and the power supply side is grounded, the three line voltages are constant and symmetrical.
2. Load side bus voltage analysis
The 35kV load side bus voltage is analyzed as follows:
Figure BDA0002307881300000062
the vector diagram of the 35kV bus voltage on the load side is shown in figure 8.
When the 35kV line is broken, the load side
Figure BDA0002307881300000063
Is composed of
Figure BDA0002307881300000064
Is equal to
Figure BDA0002307881300000065
1.2 grounding System via a resistor
1.2.135 kV line broken wire
Fig. 9 is a schematic diagram of a 35kV primary disconnection system, taking an a-phase stub as an example. The 35KV power supply system of the 35kV side transformer substation of the upper-level transformer substation is grounded through a resistor (R is generally 10, 20 and 100 omega). The power supply potentials at 35kV sides of the upper-level transformer substation are respectively set as EA、EB、EC，UNAnd if α line breaks are set for the 35kV neutral point voltage of the transformer substation on the power supply side, the capacitance to ground of the bus side of the transformer substation from the line break position to the upper level is α C, and the capacitance to ground of the bus of the transformer substation from the line break position to the load side is (1- α) C.
1. Power supply side bus voltage analysis
Analyzing to obtain the voltage of a bus at the 35kV side of the upper-level transformer substation as follows:
Figure BDA0002307881300000071
(6) in the formula (I), the compound is shown in the specification,
Figure BDA0002307881300000072
the voltage of a power side 35kV bus A1B1 line, the voltage of a B1C1 line and the voltage of a C1A1 line are respectively. The vector diagram of the 35kV bus voltage on the power supply side is shown in FIG. 10.
As can be seen from fig. 10, when a phase a of the 35kV line is disconnected, the voltages of the three-phase lines of the 35kV bus of the upper-level substation are unchanged and are kept symmetrical. With the distance of the broken line close to the power supply side bus bar different, the 0 point is 0 in FIG. 10α＝0To 0α＝1When α is equal to 1, point 0 is at 0α＝1At point, when α is 0, 0 is at 0α＝0(same below) with UNAt about ω CEAThe variation from R to 0 (the cable line capacitance C is generally less than or equal to 0.55 mu F, and the overhead line is even smaller, so UNIs a very small value, and is 0.55 mu F, U according to the grounding resistance of 20 omega, CNIs 3.45-3EAAnd so can be ignored).
2. Load side bus voltage analysis
The 35kV load side bus voltage is analyzed as follows:
Figure BDA0002307881300000073
(7) in the formula (I), the compound is shown in the specification,
Figure BDA0002307881300000074
the line voltage of the load side 35kV bus A2B2, the line voltage of B2C2 and the line voltage of C2A2 are shown in a vector diagram of the load side 35kV bus in the figure 11.
As can be seen from FIG. 11, when the 35kV line is disconnected, the load side
Figure BDA0002307881300000075
Is composed of
Figure BDA0002307881300000076
And
Figure BDA0002307881300000077
in the opposite direction and of magnitude
Figure BDA0002307881300000078
1.2.235 kV line disconnection and load side disconnection grounding
Fig. 12 is a schematic diagram of a 35kV line break and load side line break grounding primary system, taking an a-phase stub as an example. The 35KV power supply system of the 35kV side transformer substation of the upper-level transformer substation is grounded through a resistor. The power supply potentials at 35kV sides of the upper-level transformer substation are respectively set as EA、EB、EC，UNThe capacitance to ground of the 35kV bus of the transformer substation from the broken line to the upper-level substation is α C, and the capacitance to ground of the 35kV bus of the transformer substation from the broken line to the load side is (1- α) C.
1. Power supply side bus voltage analysis
The analysis was as in 1.2.1.
2. Load side bus voltage analysis
The 35kV load side bus voltage is analyzed as follows:
Figure BDA0002307881300000081
the vector diagram of the 35kV bus voltage on the load side is shown in FIG. 13.
As can be seen from FIG. 13, when the 35kV line is disconnected and the load side disconnection is grounded, U is turned offB2C2Is equal to EBCAnd the distance is different along with the distance of the broken line close to the power supply side bus. Due to UNCan be ignored, so UA2B2、UC2A2Is about equal to EBAnd EC。
1.2.335 kV line disconnection and power supply side disconnection point grounding
Fig. 14 is a schematic diagram of a primary system with a 35kV line broken and a power supply side grounded, taking an a-phase short line as an example. The 35KV power supply system of the 35kV side transformer substation of the upper-level transformer substation is grounded through a resistor. The power supply potentials at 35kV sides of the upper-level transformer substation are respectively set as EA、EB、EC，UNAs a power supplyAnd the voltage of the 35kV neutral point of the side substation transformer is α C from the broken line position to the bus side of the upper substation, and the capacitance to the ground of the 35kV bus of the load side substation from the broken line position to the load side is (1- α) C.
When the line is broken and the system side is grounded, the fault is a single-phase grounding short circuit fault, so that the zero sequence current protection action of the system transformer substation line trips, and reclosure cannot be coincided.
Analyzing the line breaking fault characteristics of the 3-66 kV line:
for three conditions of ungrounded, arc suppression coil grounded and resistance grounded systems, 35kV line breakage and load side line breakage grounded, 35kV line breakage and power supply side line breakage grounded, the power supply side line voltage is constant and symmetrical (for the resistance grounded systems, when the line breakage and system side grounded, single-phase grounding short circuit fault occurs, the zero-sequence current protection of the line trips actions).
Due to the grounding condition of the broken line of the 35kV line and the broken line of the power supply side, UNCan be ignored, so for the two conditions of 35kV line disconnection, 35kV line disconnection and grounding at the power supply side disconnection, the load side bus line voltage and the load side
Figure BDA0002307881300000082
Is equal to
Figure BDA0002307881300000083
Figure BDA0002307881300000091
Is equal to
Figure BDA0002307881300000092
For the case that the 35kV line is broken and the load side is grounded,
Figure BDA0002307881300000093
is equal to
Figure BDA0002307881300000094
α varies between 0 and 1 according to the distance of the broken line close to the power side bus,
Figure BDA0002307881300000095
in that
Figure BDA0002307881300000096
To
Figure BDA0002307881300000097
While varying between
Figure BDA0002307881300000098
In that
Figure BDA0002307881300000099
To
Figure BDA00023078813000000910
And (4) change.
In summary, when three conditions of 35kV line disconnection, 35kV line disconnection with grounding at the load side disconnection point, 35kV line disconnection with grounding at the power side disconnection point occur, the absolute value of the line voltage vector difference between the two sides of the line satisfies:
Figure BDA00023078813000000911
similarly, when a 3-66 kV line is broken, the bus line voltages on two sides of the line have the same fault characteristics.
The technical scheme of the method of the invention is as follows:
the transmission and distribution network applied by the method is 35kV single-bus subsection primary main connection (including 35kV single-bus primary main connection), 35kV inner bridging connection (shown in figure 17), 35kV expansion inner bridging connection (shown in figure 18) and 35kV line transformation group primary main connection (shown in figure 19) of a 35kV substation. Taking a 35kV substation as an example of a primary main connection of a 35kV single-bus subsection, other primary main connection protection methods are similar (in which fig. 19 is matched with a medium-voltage or low-voltage spare power automatic switch to recover power supply). The 35kV single-bus subsection primary main wiring general structure of the 35kV substation is as follows: the No. 1 power supply incoming line branch equipment and the No. 2 power supply incoming line branch equipment are respectively connected with a 35kV I section bus and a 35kV II section bus; a segmented circuit breaker 3DL is arranged between the 35kV first-segment bus and the second-segment bus, and the segmented circuit breaker 3DL is connected with a segmented current transformer CT in series; the circuit breaker 1DL is arranged at the interval of the No. 1 power supply inlet branch circuit, the circuit breaker 2DL is arranged at the interval of the No. 2 power supply inlet branch circuit, and the No. 1 power supply inlet branch circuit and the No. 2 power supply inlet branch circuit are respectively connected with a current transformer CT1 and a current transformer CT2 in series; in addition, the 35kV I section bus is also connected with a No. 1 transformer branch and a 35kV voltage transformer PT 1; the 35kV II section bus is also connected with a No. 2 transformer branch and a 35kV voltage transformer PT 2. There is circuit breaker 4DL No. 1 power inlet wire circuit power supply side, and there is circuit breaker 5DL No. 2 power inlet wire circuit power supply side. No. 1 power supply inlet wire power end 35kV bus is connected with 35kVPT3, and No. 2 power supply inlet wire power end 35kV bus is connected with 35kVPT 4. The 35kV line is provided with an optical fiber channel and line optical fiber differential protection.
Aiming at the 35kV single-bus subsection primary main connection, a scheme that voltage information on two sides of a line is transmitted through a 35kV line optical fiber channel is implemented in an upper-level substation, line voltage vector difference on the two sides of the line is compared to identify the 35kV line disconnection, a 35kV line disconnection power supply side circuit breaker or a load side circuit breaker is jumped, and power supply is recovered through a load end 35kV transformer substation spare power automatic switch is adopted, so that the field operation requirement is met.
As shown in fig. 15, the disconnection protection method for comparing the line voltage vector difference between the two sides of the line and the matching of the backup power automatic switching device of the present invention includes:
1. judging the conditions of line power supply side circuit breaker or load side circuit breaker of line breaking starting trip 35kV line breaking and power supply recovery by 35kV spare power automatic switch
1.1 judging No. 1 line disconnection tripping No. 1 35kV disconnection line power supply side circuit breaker 4DL or load side circuit breaker 1DL and starting combined standby power supply circuit breaker 2DL or 3DL by load end 35kV backup power automatic switching, and starting No. 1 35kV line disconnection alarm condition
Acquisition power source side 35kV bus PT secondary AB line voltage
Figure BDA0002307881300000101
BC line voltage
Figure BDA0002307881300000102
CA line voltage
Figure BDA0002307881300000103
Load end 35kV transformer substation I section bus PT secondary AB line voltage
Figure BDA0002307881300000104
BC line voltage
Figure BDA0002307881300000105
CA line voltage
Figure BDA0002307881300000106
(1) No. 1 35kV line 35kV power side and load end bus PT secondary line voltage:
Figure BDA0002307881300000107
and
Figure BDA0002307881300000108
and
Figure BDA0002307881300000109
and
Figure BDA00023078813000001010
the absolute value of the vector difference between every two vectors satisfies that two are more than or equal to 0.519EabAnd is not more than 0.953EabOne is less than or equal to 0.1Eab。
(2) Power end corresponds 35kV generating line PT secondary AB line voltage value UA1B1Greater than or equal to 0.9Eab1.1E or lessab；
(3) Power end corresponds 35kV generating line PT secondary BC line voltage value UB1C1Greater than or equal to 0.9Eab1.1E or lessab；
(4) Power end corresponds 35kV generating line PT secondary CA line voltage value UC1A1Greater than or equal to 0.9Eab1.1E or lessab；
(5) The power supply end 35kV line breaker 4DL of the No. 1 35kV line is at the on position.
(6) The load side 35kV line breaker 1DL of No. 1 35kV line is in the on position.
And if the conditions are all met, identifying and judging that the No. 1 35kV power line is broken, carrying out 35kV broken line protection in the 35kV line protection of the superior substation, and tripping a No. 1 35kV power line power supply side circuit breaker 4 DL. Because the No. 1 35kV power line loses power, the load end 35kV transformer substation 35kV spare power automatic switching action starts to trip off the No. 1 35kV power incoming line circuit breaker 1DL, closes the spare power circuit breaker 2DL or 3DL (or 35kV disconnection protection in the load end 35kV transformer substation No. 1 kV circuit protection, the trip No. 1 No. 35kV power line load side circuit breaker 1 DL. starts to close the spare power circuit breaker 2DL or 3DL due to the fact that the No. 1 35kV power line loses power, and the load end 35kV transformer substation 35kV spare power automatic switching action restores the transformer losing power to the spare power line for power supply. And simultaneously, starting No. 1 35kV line disconnection alarm.
1.2 judging No. 2 line disconnection tripping No. 2 35kV disconnection line power supply side circuit breaker 5DL or load side circuit breaker 2DL and starting combined standby power supply circuit breaker 1DL or 3DL by load end 35kV backup power automatic switching, and starting No. 2 35kV line disconnection alarm condition
Acquisition power source side 35kV bus PT secondary AB line voltage
Figure BDA00023078813000001011
BC line voltage
Figure BDA00023078813000001012
CA line voltage
Figure BDA00023078813000001013
Load end 35kV transformer substation I section bus PT secondary AB line voltage
Figure BDA00023078813000001014
BC line voltage
Figure BDA00023078813000001015
CA line voltage
Figure BDA00023078813000001016
(1)35kV power supply of No. 2 35kV circuitThe secondary line voltages of the side and load side busbars PT,
Figure BDA00023078813000001017
and
Figure BDA00023078813000001018
and
Figure BDA00023078813000001019
and
Figure BDA00023078813000001020
the absolute value of the vector difference between every two vectors satisfies that two are more than or equal to 0.519EabAnd is not more than 0.953EabOne is less than or equal to 0.1Eab。
(2) Power end corresponds 35kV generating line PT secondary AB line voltage value UA1B1Greater than or equal to 0.9Eab1.1E or lessab；
(3) Power end corresponds 35kV generating line PT secondary BC line voltage value UB1C1Greater than or equal to 0.9Eab1.1E or lessab；
(4) Power end corresponds 35kV generating line PT secondary CA line voltage value UC1A1Greater than or equal to 0.9Eab1.1E or lessab；
(5) And a power supply end 35kV line breaker 5DL of the No. 2 35kV line is at the switching-on position.
(6) The load side 35kV line breaker 2DL of 35kV line No. 2 is in the on position.
And if the conditions are all met, identifying and judging that the No. 2 35kV power line is broken, carrying out 35kV broken line protection in the 35kV line protection of the superior substation, and tripping a No. 2 35kV power line power supply side circuit breaker 5 DL. Because the 35kV power line 2 loses power, the 35kV substation 35kV spare power automatic switching action at the load end starts to trip off the 35kV power incoming line circuit breaker 2DL at the number 2, and closes the spare power circuit breaker 1DL or 3DL (or the 35kV disconnection protection in the protection of the 35kV line at the load end 35kV substation 2, the circuit breaker 2 DL. at the load side of the 35kV power line 2 is started to close the spare power circuit breaker 1DL or 3DL because the 35kV power line 2 loses power, so that the transformer losing power is restored to the spare power line for power supply. And simultaneously, starting No. 2 35kV line disconnection alarm.
1.3 in 1.1 and 1.2 above:
(1) the method can be applied to a transformer neutral point ungrounded mode or a system which is grounded through an arc suppression coil and grounded through a small resistor.
(2) The reason that the circuit breakers 1DL or 2DL and 4DL or 5DL on the two sides of the 35kV power inlet wire are arranged at the switching-on position is as follows: when a 35kV substation with a load end is arranged on a power supply incoming line, the bus voltage far away from the power supply incoming line can also sense the line disconnection information, and the standby power supply circuit breaker for closing of the standby automatic switching can be interfered; in addition, when a line PT is adopted, the power supply incoming line may have other load end 35kV substations, and if the power supply incoming line breaker of the load end 35kV substation trips slowly or refuses tripping, the power supply incoming line breaker of the backup automatic switching device may be interfered, and the backup automatic switching device may not act. The logic can be further optimized by adopting the condition of the 35kV power incoming line breaker at the switching-on position.
(3)EabFor the rated line voltage value of the power supply, the voltage fluctuation of the power grid is considered, and the voltage fluctuation is considered according to +/-10% of the rated voltage value of the actual power grid, wherein: when the voltage value is larger than or equal to the rated line voltage value, the rated line voltage value of the power grid is considered to be 0.9 times; the rated line voltage value is less than or equal to 1.1 times of the rated voltage value of the power grid.
1.4 after the 35kV line is identified to be broken, the tripping scheme is as follows: (1) tripping off a breaker at the power supply side of the broken line; (2) tripping off a circuit breaker on the load side of the broken line; (3) the circuit breakers on both sides of the line break are tripped together.
And 1.5, automatically transferring the load side substation bus load which is in open-phase operation due to the occurrence of line break by switching off a power supply side or load side breaker of the broken line through the backup power automatic switching device and switching on the backup power supply breaker, and restoring the load to the power supply of the backup line. And if the 35kV transformer substation adopts primary main wiring of a 35kV line transformer group, recovering the power supply task by the backup power automatic switching at the low-voltage side of the load side transformer substation.
1.6 the voltage information and the breaker position information on two sides of the line are transmitted through a line optical fiber channel.
2. The operation mode of a 35kV neutral point of a main transformer on a first section or a second section of a bus of a load end 35kV transformer substation is ungrounded; 35kV side equipment 35kV spare power automatic switching device. No. 1 and No. 2 power supply 35kV lines are required to be provided with optical fiber channels and line optical fiber differential protection.
3. The method can be implemented in a 35kV line disconnection protection device independent of a power supply end or a load end 35kV transformer substation or in a 35kV line protection device. The method is implemented in a 35kV line protection device, and has the advantage that no hardware equipment is required to be added.
The setting value of the PT secondary two-side voltage when the buses on the two sides of the 4.35kV line are broken is as follows:
dividing the secondary line voltages of a power supply side bus PT and a load end bus PT into three groups according to AB line voltage, BC line voltage and CA line voltage for comparison, wherein the setting value of the difference between the line voltages of the power supply side and the load end is as follows:
(1) two of the two groups of the setting values of the difference between the line voltage of the power supply side and the line voltage vector of the load side meet the following requirements: is greater than or equal to the rated line voltage value
Figure BDA0002307881300000121
And is less than or equal to the rated line voltage value
Figure BDA0002307881300000122
The PT secondary rated line voltage value is 100V, namely more than or equal to 51.9V and less than or equal to 95.3V;
(2) and the setting value of the difference between the line voltage of the power supply side and the line voltage vector of the load end is less than or equal to 10 percent of the rated line voltage value, namely less than or equal to 10V.
The setting value of the PT secondary line voltage of the power supply side bus meets the following requirements: the voltage value of the rated line is more than or equal to 90 percent and less than or equal to 110 percent, namely more than or equal to 90V and less than or equal to 110V.
5. The method of the invention is characterized in that the setting value of time in the single-phase disconnection relay protection method for recovering power supply by the spare power automatic switching of the load-end 35kV transformer substation is as follows:
t 1: avoiding the three-phase different-period time when the switch is switched on, and taking 0.1-0.2 second;
6. the scheme of the invention can meet the following primary main wiring: (1) a 35kV single-bus subsection primary main wiring of a 35kV transformer substation; (2) a 35kV transformer substation 35kV inner bridge primary main wiring; (3) a 35kV transformer substation 35kV enlarges primary main wiring; (4) a 35kV transformer substation 35kV line group-changing primary main wiring; (5) other primary main connections.
7. For a 35kV line with branch lines, 35kV line breakage protection of pairwise correspondence between a power end-load end substation and each load end substation needs to be implemented.
8. The scheme of the invention for comparing the bus line voltages on two sides of the line can also be used in the case of the disconnection of the 110kV line powered by a single power supply.
An example of the process of the invention is given below (taking fig. 16 as an example):
operation mode 1:
under this operational mode, 2DL of No. 2 power circuit breaker, the operation of segmentation circuit breaker 3DL, 1DL of No. 1 power circuit breaker is hot standby, 1DL of No. 1 power circuit breaker branch floodgate position promptly.
No. 1.12 35kV power line single-phase disconnection fault:
for example, if phase A is broken, phase B or phase C is broken similarly. When the phase-A single-phase disconnection fault of the No. 2 35kV power circuit occurs, abnormal operation of the circuit is sensed through the vector difference value of the voltages of the 35kV buses on the two sides, meanwhile, the voltages of the 35kV buses PT secondary of the power end transformer substation are normal, the single-phase disconnection condition of the No. 2 35kV power circuit is met, after the time delay t1, the 35kV circuit in the power end circuit protection is subjected to disconnection protection, and the circuit breaker 5DL on the power side of the No. 2 35kV power circuit is tripped. Because No. 2 35kV power supply line loses power, 35kV spare power automatic switching action of a load end 35kV transformer substation trips No. 2 kV 35kV power circuit breaker 2DL, and 1 # 35kV spare power circuit breaker 1DL is started to switch on, so that the transformer losing power is recovered to the spare No. 1 kV power supply line for power supply. And reporting the single-phase disconnection fault of the No. 2 35kV power line.
Operation mode 2:
under this operational mode, 1DL of power breaker, 3DL operation of section circuit breaker, 2 # power breaker 2DL are hot standby, 2 # power breaker 2DL separating brake position promptly.
No. 2.11 35kV power line single-phase line break fault
For example, if phase A is broken, phase B or phase C is broken similarly. When the phase-A single-phase disconnection fault of the No. 1 35kV power circuit occurs, abnormal operation of the circuit is sensed through the vector difference value of the voltages of the 35kV buses on the two sides, meanwhile, the voltages of the 35kV buses PT secondary of the power end transformer substation are normal, the single-phase disconnection condition of the No. 1 35kV power circuit is met, after the time delay t1, the 35kV circuit in the power end circuit protection is subjected to disconnection protection, and the circuit breaker 4DL on the power side of the No. 1 35kV power circuit is tripped. Because No. 1 35kV power line loses the power, the load end 35kV transformer substation 35kV spare power automatic switching action trips No. 1 kV 35kV power circuit breaker 1DL, starts No. 2 kV 35kV spare power circuit breaker 2DL to switch on, makes the transformer that loses the power restore to reserve No. 2 kV power line and supplies power on the way. And simultaneously reporting the single-phase line break fault of the No. 1 35kV power line.
Operation mode 3:
under this operational mode, 1DL of No. 1 power circuit breaker, 2DL of No. 2 power circuit breaker operate, and the hot reserve of section circuit breaker 3DL, section circuit breaker 3DL separating brake position promptly.
No. 3.11 35kV power line single-phase line break fault
For example, if phase A is broken, phase B or phase C is broken similarly. When the phase-A single-phase disconnection fault of the No. 1 35kV power circuit occurs, abnormal operation of the circuit is sensed through the vector difference value of the voltages of the 35kV buses on the two sides, meanwhile, the voltages of the 35kV buses PT secondary of the power end transformer substation are normal, the single-phase disconnection condition of the No. 1 35kV power circuit is met, after the time delay t1, the 35kV circuit in the power end circuit protection is subjected to disconnection protection, and the circuit breaker 4DL on the power side of the No. 1 35kV power circuit is tripped. Because No. 1 35kV power supply line loses the power, the load end 35kV transformer substation 35kV spare power automatic switching action trips No. 1 kV 35kV power incoming line breaker 1DL, starts the 35kV spare power supply breaker 3DL to close, and the transformer that loses the power is recovered to the spare No. 2 kV power supply line and is supplied power. And simultaneously reporting the single-phase line break fault of the No. 1 35kV power line.
3.22 # 35kV power line single-phase line break fault
For example, if phase A is broken, phase B or phase C is broken similarly. When the phase-A single-phase disconnection fault of the No. 2 35kV power circuit occurs, abnormal operation of the circuit is sensed through the vector difference value of the voltages of the 35kV buses on the two sides, meanwhile, the voltages of the 35kV buses PT secondary of the power end transformer substation are normal, the single-phase disconnection condition of the No. 2 35kV power circuit is met, after the time delay t1, the 35kV circuit in the power end circuit protection is subjected to disconnection protection, and the circuit breaker 5DL on the power side of the No. 2 35kV power circuit is tripped. Because No. 2 35kV power supply line loses power, 35kV spare power automatic switching of a load end 35kV transformer substation acts, 2DL of a No. 2 kV power supply incoming line breaker is tripped, 3DL of a 35kV spare power supply breaker is started to be switched on, and a transformer losing the power supply is recovered to a spare No. 1 kV power supply line to supply power. And reporting the single-phase disconnection fault of the No. 2 35kV power line.
In addition to the above embodiments, the present invention may have other embodiments, and any technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of the claims of the present invention.

Claims (4)

1. A method for comparing line voltage vector difference on two sides of a line with line power automatic switching matched disconnection protection is characterized by comprising the following steps:
judging the condition of line power supply side breaker or load side breaker and recovering power supply by spare power automatic switch
1.1, judging a power supply side circuit breaker 4DL or a load side circuit breaker 1DL of a No. 1 circuit disconnection jump No. 1 disconnection circuit and a standby power supply circuit breaker 2DL or 3DL started by a load side backup automatic switch, and starting a No. 1 circuit disconnection alarm condition:
collecting secondary AB line voltage of power supply side bus PT
Figure FDA0002307881290000011
BC line voltage
Figure FDA0002307881290000012
CA line voltage
Figure FDA0002307881290000013
Load end I section bus PT secondary AB line voltage of transformer substation
Figure FDA0002307881290000014
BC line voltage
Figure FDA0002307881290000015
CA line voltage
Figure FDA0002307881290000016
Conditions are as follows: (1) no. 1 line power supply side bus PT secondary AB line voltage vector
Figure FDA0002307881290000017
And load end I section bus PT secondary AB line voltage vector of transformer substation
Figure FDA0002307881290000018
Absolute value of vector difference, power supply side bus PT secondary BC line voltage vector
Figure FDA0002307881290000019
And load end I section bus PT secondary BC line voltage vector of transformer substation
Figure FDA00023078812900000110
Absolute value of vector difference, power supply side bus PT secondary CA line voltage vector
Figure FDA00023078812900000111
And load end transformer substation I section bus PT secondary CA line voltage vector
Figure FDA00023078812900000112
The absolute value of the vector difference of (1), two of the absolute values of the three vector differences being 0.519EabTo 0.953EabOne is less than or equal to 0.1Eab；EabThe rated line voltage value of the power supply;
(2) power supply end corresponding bus PT secondary AB line voltage value UA1B1Greater than or equal to 0.9Eab1.1E or lessab；
(3) Power supply end corresponding bus PT secondary BC line voltage value UB1C1Greater than or equal to 0.9Eab1.1E or lessab；
(4) Power supply end corresponding bus PT secondary CA line voltage value UC1A1Greater than or equal to 0.9Eab1.1E or lessab；
(5) The power end 35kV line breaker 4DL of the No. 1 line is at the switching-on position;
(6) the load end 35kV line breaker 1DL of the No. 1 line is at the switching-on position;
if all the conditions are met, identifying and judging that the No. 1 power line is broken, carrying out broken line protection in the line protection of a superior substation, and tripping a No. 1 power line power supply side circuit breaker 4 DL; as the No. 1 power line loses power, the load end substation spare power automatic switching action starts to trip off the No. 1 power incoming line breaker 1DL, closes the spare power breaker 2DL or 3DL, or the disconnection protection in the No. 1 line protection of the load end substation trips the No. 1 power line load side breaker 1 DL; as the No. 1 power supply circuit loses power supply, the load end transformer substation is in standby automatic switching action, and the standby power supply circuit breaker 2DL or 3DL is started to be closed, so that the transformer losing the power supply is recovered to the standby power supply circuit for supplying power; simultaneously starting No. 1 line disconnection alarm;
1.2 judging No. 2 line disconnection jumping No. 2 disconnection line power supply side circuit breaker 5DL or load side circuit breaker 2DL and load side backup power supply circuit breaker 1DL or 3DL started by load side backup automatic switch, and starting No. 2 line disconnection alarm conditions:
collecting secondary AB line voltage of power supply side bus PT
Figure FDA00023078812900000113
BC line voltage
Figure FDA00023078812900000114
CA line voltage
Figure FDA00023078812900000115
Load end I section bus PT secondary AB line voltage of transformer substation
Figure FDA00023078812900000116
BC line voltage
Figure FDA00023078812900000117
CA line voltage
Figure FDA00023078812900000118
Conditions are as follows: (1) no. 2 line power supply side bus PT secondary AB line voltage vector
Figure FDA00023078812900000119
And load end I section bus PT secondary AB line voltage vector of transformer substation
Figure FDA0002307881290000021
Absolute value of vector difference, power supply side bus PT secondary BC line voltage vector
Figure FDA0002307881290000022
And load end I section bus PT secondary BC line voltage vector of transformer substation
Figure FDA0002307881290000023
Absolute value of vector difference, power supply side bus PT secondary CA line voltage vector
Figure FDA0002307881290000024
And load end transformer substation I section bus PT secondary CA line voltage vector
Figure FDA0002307881290000025
The absolute value of the vector difference of (1), two of the absolute values of the three vector differences being 0.519EabTo 0.953EabOne is less than or equal to 0.1Eab；EabThe rated line voltage value of the power supply;
(2) power supply end corresponding bus PT secondary AB line voltage value UA1B1Greater than or equal to 0.9Eab1.1E or lessab；
(3) Power supply end corresponding bus PT secondary BC line voltage value UB1C1Greater than or equal to 0.9Eab1.1E or lessab；
(4) Power supply end corresponding bus PT secondary CA line voltage value UC1A1Greater than or equal to 0.9Eab1.1E or lessab；
(5) The power supply end circuit breaker 5DL of the No. 2 circuit is at the switching-on position;
(6) the load side line breaker 2DL of line No. 2 is in the on position;
if the conditions are all met, identifying and judging that the No. 2 power line is broken, carrying out broken line protection in the line protection of a superior substation, and tripping a No. 2 power line power supply side circuit breaker 5 DL; as the No. 2 power supply line loses power supply, the load end substation is in standby automatic switching action, the No. 2 power supply incoming line breaker 2DL is started to be tripped, the standby power supply breaker 1DL or 3DL is closed, or the line break protection in the No. 2 line protection of the load end substation is used for tripping the No. 2 power supply line load side breaker 2 DL; as the No. 2 power supply circuit loses power supply, the load end transformer substation is in standby automatic switching action, and the standby power supply circuit breaker 1DL or 3DL is started to be closed, so that the transformer losing the power supply is recovered to the standby power supply circuit for supplying power; and simultaneously, starting No. 2 line disconnection alarm.
2. The method for protecting the disconnection of the line by comparing the vector difference of the line voltages on two sides of the line with the automatic backup switch as claimed in claim 1, which is applied to a mode that a neutral point of a transformer is not grounded or is grounded through an arc suppression coil and a low-resistance grounding system.
3. The method for protecting against disconnection of power automatic switching device by comparing the vector difference of line voltages on two sides of line as claimed in claim 1, wherein the secondary side rated line voltage value E of PTabIs 100V.
4. The method for protecting the line breaking by comparing the line voltage vector difference on the two sides of the line with the automatic standby switch as claimed in claim 1, wherein t1 is 0.1-0.2 second when the three phases are not in phase when the breaker is closed.
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008309681A (en) * 2007-06-15 2008-12-25 Hitachi Industrial Equipment Systems Co Ltd Insulation deterioration monitoring device and its method
CN101452041A (en) * 2008-12-26 2009-06-10 湖北省电力试验研究院 Electrical power distribution network single-phase earth fault type and phase distinguishing method
CN106169740A (en) * 2016-08-29 2016-11-30 国网江苏省电力公司镇江供电公司 110kV single-trunk segmental wiring incoming relay-protection locking prepared auto restart relay protecting method
CN106291219A (en) * 2016-10-10 2017-01-04 国网四川省电力公司技能培训中心 Single-phase earthing/PT disconnection fault automatic discrimination alarm device and method
CN106340954A (en) * 2016-10-13 2017-01-18 国家电网公司 Method for identifying line breaking of power supply line and switching to standby power supply
CN107104421A (en) * 2017-04-13 2017-08-29 华南理工大学 A kind of voltage longitudinal protection method of distribution network comprising inverse distributed power
CN109738758A (en) * 2019-01-22 2019-05-10 贵州电网有限责任公司 A kind of distribution line fault type judgment method based on voltage characteristic

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008309681A (en) * 2007-06-15 2008-12-25 Hitachi Industrial Equipment Systems Co Ltd Insulation deterioration monitoring device and its method
CN101452041A (en) * 2008-12-26 2009-06-10 湖北省电力试验研究院 Electrical power distribution network single-phase earth fault type and phase distinguishing method
CN106169740A (en) * 2016-08-29 2016-11-30 国网江苏省电力公司镇江供电公司 110kV single-trunk segmental wiring incoming relay-protection locking prepared auto restart relay protecting method
CN106291219A (en) * 2016-10-10 2017-01-04 国网四川省电力公司技能培训中心 Single-phase earthing/PT disconnection fault automatic discrimination alarm device and method
CN106340954A (en) * 2016-10-13 2017-01-18 国家电网公司 Method for identifying line breaking of power supply line and switching to standby power supply
CN107104421A (en) * 2017-04-13 2017-08-29 华南理工大学 A kind of voltage longitudinal protection method of distribution network comprising inverse distributed power
CN109738758A (en) * 2019-01-22 2019-05-10 贵州电网有限责任公司 A kind of distribution line fault type judgment method based on voltage characteristic

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
常仲乐等: "基于零序电压幅值差的配电网断线识别与隔离", 《电力系统自动化》 *

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