CN110912093B - Disconnection relay protection method for measuring matching of load side bus line voltage and spare power automatic switching - Google Patents

Disconnection relay protection method for measuring matching of load side bus line voltage and spare power automatic switching Download PDF

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CN110912093B
CN110912093B CN201911247205.9A CN201911247205A CN110912093B CN 110912093 B CN110912093 B CN 110912093B CN 201911247205 A CN201911247205 A CN 201911247205A CN 110912093 B CN110912093 B CN 110912093B
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line
power supply
line voltage
disconnection
power
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CN110912093A (en
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刘昶
胡浩
汤勋
朱文韬
姜正驰
孙东杰
赵伟
周杨
陈泽
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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
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H1/00—Details of emergency protective circuit arrangements
    • H02H1/0007—Details of emergency protective circuit arrangements concerning the detecting means
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H5/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal non-electric working conditions with or without subsequent reconnection
    • H02H5/10—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal non-electric working conditions with or without subsequent reconnection responsive to mechanical injury, e.g. rupture of line, breakage of earth connection
    • 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
    • H02H7/22—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 for distribution gear, e.g. bus-bar systems; for switching devices

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Abstract

The invention discloses a disconnection relay protection method for measuring the matching of load side bus line voltage and spare power automatic switching, which is applied to a power transmission and distribution network. The invention adopts the load-end substation to judge the single-phase line break of the power line, starts the remote tripping function of the optical fiber differential protection of the line through the power line, remotely trips the circuit breaker at the power supply side of the line or trips the circuit breaker at the load side, and then starts the tripping inlet line circuit breaker and closes the standby power circuit breaker by the backup automatic switching action of the load-end substation, so that the transformer losing the power supply can be recovered to the standby power supply for supplying power.

Description

Disconnection relay protection method for measuring matching of load side bus line voltage and spare power automatic switching
Technical Field
The invention relates to a disconnection relay protection method for measuring the matching of load side bus line voltage and spare power automatic switching, belonging 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 for identifying a 3-66 kV line disconnection, a line-jumping power supply side circuit breaker or a load side circuit breaker and recovering power supply through a load end 3-66 kV substation backup power automatic switch by identifying the abnormal voltage of a load end bus line in a load end substation, and aims to solve the problems in the prior art.
Disclosure of Invention
The invention aims to provide a disconnection relay protection method for measuring the matching of load side bus line voltage and automatic backup power switching, which is applied to a power transmission and distribution network and used for identifying line disconnection at a load end 3-66 kV transformer substation, identifying single-phase line disconnection of a 35kV line through the bus voltage at the load end of the line, starting a power supply side circuit breaker or a load side circuit breaker of a trip line circuit and recovering power supply from the automatic backup power switching of the load end 3-66 kV transformer substation.
The purpose of the invention is realized by the following technical scheme:
a method for measuring a broken line relay protection method of matching of a load side bus line voltage and a spare power automatic switching device comprises the following steps:
control method for recognizing each phase disconnection of circuit
Method for identifying each phase disconnection of No. 1.11 power supply incoming line circuit
Collection load end I section generating line PT secondary AB line voltage of transformer substation
Figure BDA0002307878570000011
BC line voltage
Figure BDA0002307878570000012
CA line voltage
Figure BDA0002307878570000013
1) A-phase broken line identification method
(1) PT secondary AB line of I section busPressure value UA2B2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(2) Line voltage value U of secondary BC line of PT (potential transformer) of I-section busB2C2Greater than or equal to 0.9 times of rated power line voltage EabLess than or equal to 1.1 times rated power line voltage Eab；
(3) Line voltage value U of PT secondary CA of I-section busC2A2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(4) Line voltage vector of PT secondary line of I-section bus
Figure BDA0002307878570000014
And
Figure BDA0002307878570000015
the included angle is between-5 degrees and 35 degrees;
(5) line voltage vector of PT secondary line of I-section bus
Figure BDA0002307878570000021
And
Figure BDA0002307878570000022
the included angle is between-5 degrees and 35 degrees;
(6) the load end breaker 1DL of line 1 is in the on position;
when the conditions are all met, a phase disconnection signal of a No. 1 power supply incoming line circuit A is sent out after a delay t 2;
2) method for identifying B-phase broken line
(1) Line voltage value U of PT secondary AB line of I-section busA2B2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(2) Line voltage value U of secondary BC line of PT (potential transformer) of I-section busB2C2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(3) Line voltage value U of PT secondary CA of I-section busC2A2Greater than or equal to 0.9 times of rated power line voltage EabLess than or equal to 1.1 times rated power line voltage Eab；
(4) Line voltage vector of PT secondary line of I-section bus
Figure BDA0002307878570000023
And
Figure BDA0002307878570000024
the included angle is between-5 degrees and 35 degrees;
(5) line voltage vector of PT secondary line of I-section bus
Figure BDA0002307878570000025
And
Figure BDA0002307878570000026
the included angle is between-5 degrees and 35 degrees;
(6) the load end breaker 1DL of line 1 is in the on position;
when the conditions are all met, a phase B disconnection signal of a No. 1 power supply incoming line circuit is sent out after a delay t 2;
3) control method for C-phase broken line identification
(1) Line voltage value U of PT secondary AB line of I-section busA2B2Greater than or equal to 0.9 times of rated power line voltage EabLess than or equal to 1.1 times rated power line voltage Eab；
(2) Line voltage value U of secondary BC line of PT (potential transformer) of I-section busB2C2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(3) Line voltage value U of PT secondary CA of I-section busC2A2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(4) Line voltage vector of PT secondary line of I-section bus
Figure BDA0002307878570000027
And
Figure BDA0002307878570000028
the included angle is between-5 degrees and 35 degrees;
(5) line voltage vector of PT secondary line of I-section bus
Figure BDA0002307878570000029
And
Figure BDA00023078785700000210
the included angle is between-5 degrees and 35 degrees;
(6) the load end breaker 1DL of line 1 is in the on position;
when the conditions are all met, a phase C disconnection signal of a No. 1 power supply incoming line circuit is sent out after a delay t 2;
method for identifying each phase disconnection of No. 1.22 power supply incoming line circuit
Acquiring secondary AB line voltage of II-section bus PT of load-end transformer substation
Figure BDA00023078785700000211
BC line voltage
Figure BDA00023078785700000212
CA line voltage
Figure BDA00023078785700000213
1) A-phase broken line identification method
(1) II section bus PT secondary AB line voltage value UA2B2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(2) II-section bus PT secondary BC line voltage value UB2C2Greater than or equal to 0.9 times of rated power line voltage EabLess than or equal to 1.1 times rated power line voltage Eab；
(3) II-section bus PT secondary CA line voltage value UC2A2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(4) II-section bus PT secondary line voltage vector
Figure BDA0002307878570000031
And
Figure BDA0002307878570000032
the included angle is between-5 degrees and 35 degrees;
(5) II-section bus PT secondary line voltage vector
Figure BDA0002307878570000033
And
Figure BDA0002307878570000034
the included angle is between-5 degrees and 35 degrees;
(6) the load side breaker 2DL of line No. 2 is in the on position;
when the conditions are all met, a phase disconnection signal of a No. 2 power supply incoming line circuit A is sent out after a delay t 1;
2) control method for B-phase broken line identification
(1) II section bus PT secondary AB line voltage value UA2B2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(2) II-section bus PT secondary BC line voltage value UB2C2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(3) II-section bus PT secondary CA line voltage value UC2A2Greater than or equal to 0.9 times of rated power line voltage EabLess than or equal to 1.1 times rated power line voltage Eab；
(4) II-section bus PT secondary line voltage vector
Figure BDA0002307878570000035
And
Figure BDA0002307878570000036
the included angle is between-5 degrees and 35 degrees;
(5) II-section bus PT secondary line voltage vector
Figure BDA0002307878570000037
And
Figure BDA0002307878570000038
the included angle is between-5 degrees and 35 degrees;
(6) the load side breaker 2DL of line No. 2 is in the on position;
when the conditions are all met, a No. 2 power supply incoming line B phase disconnection signal of the 35kV line is sent out after time delay t 1;
3) c-phase broken line identification method
(1) II section bus PT secondary AB line voltage value UA2B2Greater than or equal to 0.9 times of rated power line voltage EabLess than or equal to 1.1 times rated power line voltage Eab；
(2) II-section bus PT secondary BC line voltage value UB2C2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(3) II-section bus PT secondary CA line voltage value UC2A2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(4) II-section bus PT secondary line voltage vector
Figure BDA0002307878570000039
And
Figure BDA00023078785700000310
the included angle is between-5 degrees and 35 degrees;
(5) II-section bus PT secondary line voltage vector
Figure BDA00023078785700000311
And
Figure BDA00023078785700000312
the included angle is between-5 degrees and 35 degrees;
(6) the load side breaker 2DL of line No. 2 is in the on position;
when the conditions are all met, a phase C disconnection signal of a No. 2 power supply incoming line circuit is sent out after a delay t 1;
judging the condition of starting the circuit breaking to trip the circuit breaker at the power supply side or the load side and recovering the power supply by the spare power automatic switch
2.1 conditions for judging No. 1 line disconnection jumping No. 1 line disconnection line load side circuit breaker 1DL and switching standby power supply circuit breaker 2DL or 3DL by load side standby power automatic switching start
If any one of the A-phase disconnection identification method, the B-phase disconnection identification method and the C-phase disconnection identification method in the 1 # power inlet line disconnection identification methods is met, identifying and judging that the 1 # power line is disconnected, performing disconnection protection in load end substation line protection, and starting a far jump 1 # power line power supply side circuit breaker 4DL through line optical fiber differential protection; because the power supply line 1 loses power, the load end substation spare power automatic switching action starts to trip out the power supply incoming line breaker 1DL, the spare power supply breaker 2DL or 3DL is closed, or the line break protection in the load end substation 1 line protection, because the power supply line 1 loses power, the load end substation spare power automatic switching action starts to close the spare power supply breaker 2DL or 3DL, so that the transformer losing power is restored to the spare power supply line for power supply, and the line break alarm of the line 1 is started at the same time;
2.2 conditions for judging No. 2 line disconnection jumping No. 2 disconnection line power supply side circuit breaker 5DL or load side circuit breaker 2DL and switching standby power supply circuit breaker 1DL or 3DL by load side backup power automatic switching start
If any one of the method for identifying phase A disconnection, the method for identifying phase B disconnection and the method for identifying phase C disconnection in the method for identifying the phase 2 power incoming line is satisfied, identifying and judging that the phase 2 power incoming line is disconnected, protecting the disconnection in the load-side substation line protection, and starting a far-jump phase 2 power line power-side circuit breaker 5DL through line optical fiber differential protection; as the No. 2 power supply line loses power supply, the load end substation spare power automatic switching action starts to trip off the No. 2 power supply incoming line breaker 2DL, and closes the spare power supply breaker 1DL or 3DL, or the line break protection in the No. 2 line protection of the load end substation trips 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 relay protection method for measuring the voltage of the load side bus 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 measuring the load side bus line voltage and the disconnection relay protection matched with the backup power automatic switching device comprises the step of measuring the PT secondary side rated line voltage value EabIs 100V.
According to the method for measuring the line break relay protection by matching the load side bus line voltage with the automatic bus transfer, t1 is 0.1-0.2 second when three phases are not in phase when the breaker is switched on; t2 is taken to be 5-7 seconds.
Compared with the prior art, the invention has the beneficial effects that:
1. the method fully utilizes the fault characteristics of the secondary line voltage of the load-side substation bus PT when the single-phase line is broken, and identifies the simple and easy operation of the line single-phase line breaking and line jumping power supply side circuit breaker or the load side circuit breaker.
2. The invention adopts the load-end substation to judge the single-phase line break of the power line, starts the remote tripping function of the optical fiber differential protection of the line through the power line, remotely trips the circuit breaker (or the circuit breaker at the load side) at the power supply side of the line, and then starts the tripping inlet line circuit breaker and closes the standby power circuit breaker by the spare power automatic switching action of the load-end substation, so that the transformer losing the power supply recovers to the relay protection scheme of the power supply on the standby power supply, thereby effectively preventing the influence of the phase-lacking power supply of the transformer on the power grid and the load power supply and being beneficial to the safe and stable.
3. The invention adopts the No. 1 (or No. 2) incoming line breaker added into the load end transformer substation to judge the switching-on position, thereby preventing the false action of the disconnection protection.
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，UNIf alpha is broken for the 35kV neutral point voltage of the transformer of the power side transformer substation, the capacitance to ground of the bus side of the transformer substation from the broken line to the upper level is alpha C, and the capacitance to ground of the 35kV bus of the transformer substation from the broken line to the load side is (1-alpha) 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 BDA0002307878570000061
(1) in the formula (I), the compound is shown in the specification,
Figure BDA0002307878570000062
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 BDA0002307878570000063
the voltage of the 35kV side power line of the upper-level transformer substation is equal. The vector diagram of the voltage of the 35kV bus on the power supply side is shown in fig. 2, and as can be seen from fig. 2, when the phase A of the 35kV line is disconnected, the voltage of the three-phase line of the 35kV bus of the upper-level substation is unchanged and keeps symmetry. In the figure, alpha varies between 0 and 1, and 0 point is 0 in FIG. 2α＝0To 0α＝1When α is 1, point 0 is 0α＝1At the point, when α is 0, 0 is 0α＝0(the same applies below).
2. Load side bus voltage analysis
The 35kV load side bus voltage is analyzed as follows:
Figure BDA0002307878570000064
(2) in the formula (I), the compound is shown in the specification,
Figure BDA0002307878570000065
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 BDA0002307878570000066
Is composed of
Figure BDA0002307878570000067
And
Figure BDA0002307878570000068
in the opposite direction and of magnitude
Figure BDA0002307878570000069
1.1.235kV 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 voltage of a 35kV neutral point of a transformer substation on a power supply side is alpha C on the bus side of a transformer substation from a broken line to a superior substation, and the capacitance of the 35kV bus of the transformer substation from the broken line to a load side is (1-alpha) 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 BDA0002307878570000071
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 BDA0002307878570000072
is equal to
Figure BDA0002307878570000073
Along with the difference of the distance of the broken line close to the power supply side bus, alpha varies between 0 and 1, and simultaneously
Figure BDA0002307878570000074
In that
Figure BDA0002307878570000075
To a change of 0, point 0 being as in FIG. 5 0α＝0To 0α＝1The number of the intermediate change is changed,
Figure BDA0002307878570000076
is as large as
Figure BDA0002307878570000077
Change to EBWhile varying between
Figure BDA0002307878570000078
Size of (2)
Figure BDA0002307878570000079
Change to ECAnd (4) change. 1.1.335kV 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 voltage of a 35kV neutral point of a transformer substation on a power supply side is alpha C on the bus side of a transformer substation from a broken line to a superior substation, and the capacitance of the 35kV bus of the transformer substation from the broken line to a load side is (1-alpha) 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 BDA00023078785700000710
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 BDA0002307878570000081
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 BDA0002307878570000082
Is composed of
Figure BDA0002307878570000083
And
Figure BDA0002307878570000084
in the opposite direction and of magnitude
Figure BDA0002307878570000085
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，UNIf alpha is broken for the 35kV neutral point voltage of the transformer of the power side transformer substation, the broken line reachesThe capacitance to ground of the bus of the upper-level substation is alpha C, and the capacitance to ground of the 35kV bus of the substation from the broken line to the load side is (1-alpha) 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 BDA0002307878570000086
(6) in the formula (I), the compound is shown in the specification,
Figure BDA0002307878570000087
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 1, point 0 is 0α＝1At the point, when α is 0, 0 is 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 BDA0002307878570000091
(7) in the formula (I), the compound is shown in the specification,
Figure BDA0002307878570000092
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 BDA0002307878570000093
Is composed of
Figure BDA0002307878570000094
And
Figure BDA0002307878570000095
in the opposite direction and of magnitude
Figure BDA0002307878570000096
1.2.235kV 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 voltage of a 35kV neutral point of a transformer substation on a power supply side is alpha C on the bus side of a transformer substation from a broken line to a superior substation, and the capacitance of the 35kV bus of the transformer substation from the broken line to a load side is (1-alpha) 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 BDA0002307878570000097
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，UNThe voltage of a 35kV neutral point of a transformer substation on a power supply side is alpha C on the bus side of a transformer substation from a broken line to a superior substation, and the capacitance of the 35kV bus of the transformer substation from the broken line to a load side is (1-alpha) 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 BDA0002307878570000101
Is equal to
Figure BDA0002307878570000102
Figure BDA0002307878570000103
And
Figure BDA0002307878570000104
in the opposite direction and of magnitude
Figure BDA0002307878570000105
For the case that the 35kV line is broken and the load side is grounded,
Figure BDA0002307878570000106
is equal to
Figure BDA0002307878570000107
Alpha varies between 0 and 1 according to the distance between the broken line and the bus on the power supply side,
Figure BDA0002307878570000108
is as large as
Figure BDA0002307878570000109
Change to EBWhile varying between
Figure BDA00023078785700001010
Is as large as
Figure BDA00023078785700001011
Change to ECAnd (4) change.
In summary, when three conditions of 35kV line disconnection, 35kV line disconnection and grounding at the load side disconnection point, 35kV line disconnection and grounding at the power side disconnection point occur, the load side bus line voltage satisfies:
Figure BDA00023078785700001012
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 of the invention is 35kV single-bus subsection primary main connection (including 35kV single-bus primary main connection), 35kV inner bridging connection (as shown in figure 17), 35kV expansion inner bridging connection (as shown in figure 18), 35kV line-to-group primary main connection (as shown in figure 19) of a 35kV substation, and the like. Taking the primary main connection of a 35kV single bus subsection in a 35kV substation as an example, the protection method of other primary main connections is similar. 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 and the 35kV single-phase broken line protection, a long-jump 35kV line power supply side circuit breaker (or a broken line load side circuit breaker) is started through 35kV line optical fiber differential protection, and a single-phase broken line relay protection scheme for restoring power supply through a load end 35kV substation backup power automatic switch is adopted to meet the field operation requirement. The protection method and logic are implemented in 35kV backup protection of a load end 35kV transformer substation or 35kV line protection.
As shown in fig. 15, the method for measuring the disconnection relay protection of the load side bus line voltage and the spare power automatic switching device in the invention comprises the following steps:
control method for recognizing each phase disconnection of circuit
Method for identifying each phase disconnection of No. 1.11 power supply incoming line circuit
Collection load end I section generating line PT secondary AB line voltage of transformer substation
Figure BDA0002307878570000111
BC line voltage
Figure BDA0002307878570000112
CA line voltage
Figure BDA0002307878570000113
1) A-phase broken line identification method
(1) Line voltage value U of PT secondary AB line of I-section busA2B2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(2) Line voltage value U of secondary BC line of PT (potential transformer) of I-section busB2C2Greater than or equal to 0.9 times of rated power line voltage EabLess than or equal to 1.1 times rated power line voltage Eab；
(3) Line voltage value U of PT secondary CA of I-section busC2A2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(4) Line voltage vector of PT secondary line of I-section bus
Figure BDA0002307878570000114
And
Figure BDA0002307878570000115
the included angle is between-5 degrees and 35 degrees;
(5) line voltage vector of PT secondary line of I-section bus
Figure BDA0002307878570000116
And
Figure BDA0002307878570000117
the included angle is between-5 degrees and 35 degrees;
(6) the load end breaker 1DL of line 1 is in the on position;
when the conditions are all met, a phase disconnection signal of a No. 1 power supply incoming line circuit A is sent out after a delay t 2;
2) method for identifying B-phase broken line
(1) Line voltage value U of PT secondary AB line of I-section busA2B2Power line with 0.45 times or more of rated power linePressure EabLess than or equal to 0.635 times of rated power line voltage Eab；
(2) Line voltage value U of secondary BC line of PT (potential transformer) of I-section busB2C2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(3) Line voltage value U of PT secondary CA of I-section busC2A2Greater than or equal to 0.9 times of rated power line voltage EabLess than or equal to 1.1 times rated power line voltage Eab；
(4) Line voltage vector of PT secondary line of I-section bus
Figure BDA0002307878570000121
And
Figure BDA0002307878570000122
the included angle is between-5 degrees and 35 degrees;
(5) line voltage vector of PT secondary line of I-section bus
Figure BDA0002307878570000123
And
Figure BDA0002307878570000124
the included angle is between-5 degrees and 35 degrees;
(6) the load end breaker 1DL of line 1 is in the on position;
when the conditions are all met, a phase B disconnection signal of a No. 1 power supply incoming line circuit is sent out after a delay t 2;
3) control method for C-phase broken line identification
(1) Line voltage value U of PT secondary AB line of I-section busA2B2Greater than or equal to 0.9 times of rated power line voltage EabLess than or equal to 1.1 times rated power line voltage Eab；
(2) Line voltage value U of secondary BC line of PT (potential transformer) of I-section busB2C2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(3) Line voltage value U of PT secondary CA of I-section busC2A2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(4) Line voltage vector of PT secondary line of I-section bus
Figure BDA0002307878570000125
And
Figure BDA0002307878570000126
the included angle is between-5 degrees and 35 degrees;
(5) line voltage vector of PT secondary line of I-section bus
Figure BDA0002307878570000127
And
Figure BDA0002307878570000128
the included angle is between-5 degrees and 35 degrees;
(6) the load end breaker 1DL of line 1 is in the on position;
when the conditions are all met, a phase C disconnection signal of a No. 1 power supply incoming line circuit is sent out after a delay t 2;
method for identifying each phase disconnection of No. 1.22 power supply incoming line circuit
Acquiring secondary AB line voltage of II-section bus PT of load-end transformer substation
Figure BDA0002307878570000129
BC line voltage
Figure BDA00023078785700001210
CA line voltage
Figure BDA00023078785700001211
1) A-phase broken line identification method
(1) II section bus PT secondary AB line voltage value UA2B2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(2) II-section bus PT secondary BC line voltage value UB2C2Greater than or equal to 0.9 times of rated power line voltage EabIs less than or equal toAt 1.1 times rated power line voltage Eab；
(3) II-section bus PT secondary CA line voltage value UC2A2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(4) II-section bus PT secondary line voltage vector
Figure BDA00023078785700001212
And
Figure BDA00023078785700001213
the included angle is between-5 degrees and 35 degrees;
(5) II-section bus PT secondary line voltage vector
Figure BDA0002307878570000131
And
Figure BDA0002307878570000132
the included angle is between-5 degrees and 35 degrees;
(6) the load side breaker 2DL of line No. 2 is in the on position;
when the conditions are all met, a phase disconnection signal of a No. 2 power supply incoming line circuit A is sent out after a delay t 1;
2) control method for B-phase broken line identification
(1) II section bus PT secondary AB line voltage value UA2B2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(2) II-section bus PT secondary BC line voltage value UB2C2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(3) II-section bus PT secondary CA line voltage value UC2A2Greater than or equal to 0.9 times of rated power line voltage EabLess than or equal to 1.1 times rated power line voltage Eab；
(4) II-section bus PT secondary line voltage vector
Figure BDA0002307878570000133
And
Figure BDA0002307878570000134
the included angle is between-5 degrees and 35 degrees;
(5) II-section bus PT secondary line voltage vector
Figure BDA0002307878570000135
And
Figure BDA0002307878570000136
the included angle is between-5 degrees and 35 degrees;
(6) the load side breaker 2DL of line No. 2 is in the on position;
when the conditions are all met, a No. 2 power supply incoming line B phase disconnection signal of the 35kV line is sent out after time delay t 1;
3) c-phase broken line identification method
(1) II section bus PT secondary AB line voltage value UA2B2Greater than or equal to 0.9 times of rated power line voltage EabLess than or equal to 1.1 times rated power line voltage Eab；
(2) II-section bus PT secondary BC line voltage value UB2C2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(3) II-section bus PT secondary CA line voltage value UC2A2Greater than or equal to 0.45 times of rated power line voltage EabLess than or equal to 0.635 times of rated power line voltage Eab；
(4) II-section bus PT secondary line voltage vector
Figure BDA0002307878570000137
And
Figure BDA0002307878570000138
the included angle is between-5 degrees and 35 degrees;
(5) II-section bus PT secondary line voltage vector
Figure BDA0002307878570000139
And
Figure BDA00023078785700001310
the included angle is between-5 degrees and 35 degrees;
(6) the load side breaker 2DL of line No. 2 is in the on position;
when the conditions are all met, a phase C disconnection signal of a No. 2 power supply incoming line circuit is sent out after a delay t 1;
judging the condition of starting the circuit breaking to trip the circuit breaker at the power supply side or the load side and recovering the power supply by the spare power automatic switch
2.1 conditions for judging No. 1 line disconnection jumping No. 1 line disconnection line load side circuit breaker 1DL and switching standby power supply circuit breaker 2DL or 3DL by load side standby power automatic switching start
If any one of the A-phase disconnection identification method, the B-phase disconnection identification method and the C-phase disconnection identification method in the 1 # power inlet line disconnection identification methods is met, identifying and judging that the 1 # power line is disconnected, performing disconnection protection in load end substation line protection, and starting a far jump 1 # power line power supply side circuit breaker 4DL through line optical fiber differential protection; because the power supply line 1 loses power, the load end substation spare power automatic switching action starts to trip out the power supply incoming line breaker 1DL, the spare power supply breaker 2DL or 3DL is closed, or the line break protection in the load end substation 1 line protection, because the power supply line 1 loses power, the load end substation spare power automatic switching action starts to close the spare power supply breaker 2DL or 3DL, so that the transformer losing power is restored to the spare power supply line for power supply, and the line break alarm of the line 1 is started at the same time;
2.2 conditions for judging No. 2 line disconnection jumping No. 2 disconnection line power supply side circuit breaker 5DL or load side circuit breaker 2DL and switching standby power supply circuit breaker 1DL or 3DL by load side backup power automatic switching start
If any one of the method for identifying phase A disconnection, the method for identifying phase B disconnection and the method for identifying phase C disconnection in the method for identifying the phase 2 power incoming line is satisfied, identifying and judging that the phase 2 power incoming line is disconnected, protecting the disconnection in the load-side substation line protection, and starting a far-jump phase 2 power line power-side circuit breaker 5DL through line optical fiber differential protection; as the No. 2 power supply line loses power supply, the load end substation spare power automatic switching action starts to trip off the No. 2 power supply incoming line breaker 2DL, and closes the spare power supply breaker 1DL or 3DL, or the line break protection in the No. 2 line protection of the load end substation trips 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.
2.3 in 2.1 and 2.2 above:
(1) the method can be applied to a transformer neutral point ungrounded mode or arc suppression coil grounded mode and a small-resistance grounded system.
(2) The reason that the breaker 1DL or 2DL on the inlet wire load side of the 35kV power supply is adopted 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.
(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.
(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.
(5) For the bus load of the load side transformer substation which causes the line break and the phase loss operation, a power supply side or load side breaker of a line break line is tripped by the spare power automatic switching device, and the spare power supply breaker is closed to automatically transfer the load and restore the power supply to the spare 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.
3. 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.
4. The method can be implemented in a single 35kV line disconnection protection device of a load-end 35kV transformer substation or 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.
5. The load end 35kV transformer substation 35kV bus line breaking phase PT secondary setting value is as follows:
the overall setting principle is as follows: at. + -. 10% of the corresponding theoretical value.
(1) Setting PT secondary line voltage between the broken line phase and the other two phases without broken line, wherein the setting value is greater than or equal to 45% (0.9 x 0.5) of rated line voltage value and less than or equal to 63.5% of rated line voltage value
Figure BDA0002307878570000151
The PT secondary rated line voltage value is 100V, namely is more than or equal to 45 and less than or equal to 63.5V;
(2) the PT secondary line voltage setting value between two unbroken line phases is greater than or equal to 90% of the rated line voltage value and less than or equal to 110% of the rated line voltage value, and the PT secondary rated line voltage value is 100V, namely greater than or equal to 90V and less than or equal to 110V.
(3) The included angle between the line voltage vector of the broken line phase and the line voltage vector of the unbroken line phase is enlarged by +/-5 degrees from a theoretical value, namely more than or equal to-5 degrees and less than or equal to 35 degrees.
6. The setting value of time in the single-phase disconnection relay protection method for judging the 35kV line power supply side circuit breaker is as follows:
(1) t 1: avoiding the three-phase different-period time when the breaker is switched on, and taking 0.1-0.2 second;
(2) t 2: taking for 5-7 seconds.
7. 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.
8. The scheme of the invention can also be used in the case of the disconnection of a 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.
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. 235kV power line occurs, abnormal operation of the line is sensed through the line voltage value of a load side 35kV bus and the line voltage vector included angle, the single-phase disconnection condition of the No. 235kV power line is met, a disconnection signal is reported after the time delay of t2, the 35kV line in power end line protection is subjected to disconnection protection after the time delay of t1, and the circuit breaker 5DL on the power side of the No. 235kV power line is jumped. Because No. 235kV 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 simultaneously, sending a single-phase disconnection fault of a No. 1 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.
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 line occurs, abnormal operation of the line is sensed through the line voltage value of a load side 35kV bus and the line voltage vector included angle, the single-phase disconnection condition of the No. 1 35kV power line is met, a disconnection signal is reported after the time delay of t2, the 35kV line in power end line protection is subjected to disconnection protection after the time delay of t1, and a circuit breaker 4DL on the power side of the No. 1 35kV power line is jumped. 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.
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. 1 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. 1 35kV power line occurs, abnormal operation of the line is sensed through the line voltage value of a load side 35kV bus and the line voltage vector included angle, the single-phase disconnection condition of the No. 1 35kV power line is met, a disconnection signal is reported after the time delay of t2, the 35kV line in power end line protection is subjected to disconnection protection after the time delay of t1, and a circuit breaker 4DL on the power side of the No. 1 35kV power line is jumped. 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.
No. 235kV 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. 235kV power line occurs, abnormal operation of the line is sensed through the line voltage value of a load side 35kV bus and the line voltage vector included angle, the single-phase disconnection condition of the No. 235kV power line is met, a disconnection signal is reported after the time delay of t2, the 35kV line in power end line protection is subjected to disconnection protection after the time delay of t1, and the circuit breaker 5DL on the power side of the No. 235kV power line is jumped. Because No. 235kV power 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 35kV spare power circuit breaker 3DL is started to switch on, so that the transformer losing power is recovered to the spare No. 1 kV power line for power supply.
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 measuring the disconnection relay protection method of the matching of the load side bus line voltage and the spare power automatic switching is characterized by comprising the following steps:
control method for recognizing each phase disconnection of circuit
Method for identifying each phase disconnection of No. 1.11 power supply incoming line circuit
Collection load end I section generating line PT secondary AB line voltage of transformer substation
Figure FDA0002881760010000011
BC line voltage
Figure FDA0002881760010000012
CA line voltage
Figure FDA0002881760010000013
1) A-phase broken line identification method
(1) Line voltage value U of PT secondary AB line of I-section busA2B2Greater than or equal to 0.45Eab0.635E or lessab；EabThe voltage value of a PT secondary side rated line;
(2) line voltage value U of secondary BC line of PT (potential transformer) of I-section busB2C2Greater than or equal to 0.9Eab1.1E or lessab；
(3) Line voltage value U of PT secondary CA of I-section busC2A2Greater than or equal to 0.45Eab0.635E or lessab；
(4) Line voltage vector of PT secondary line of I-section bus
Figure FDA0002881760010000014
And
Figure FDA0002881760010000015
at an included angle of-5 to 35 degrees;
(5) line voltage vector of PT secondary line of I-section bus
Figure FDA0002881760010000016
And
Figure FDA0002881760010000017
the included angle is between-5 degrees and 35 degrees;
(6) the load end breaker 1DL of line 1 is in the on position;
when the conditions are all met, a phase disconnection signal of a No. 1 power supply incoming line circuit A is sent out after a delay t 2;
2) method for identifying B-phase broken line
(1) Line voltage value U of PT secondary AB line of I-section busA2B2Greater than or equal to 0.45Eab0.635E or lessab；
(2) Line voltage value U of secondary BC line of PT (potential transformer) of I-section busB2C2Greater than or equal to 0.45Eab0.635E or lessab；
(3) Line voltage value U of PT secondary CA of I-section busC2A2Greater than or equal to 0.9Eab1.1E or lessab；
(4) Line voltage vector of PT secondary line of I-section bus
Figure FDA0002881760010000018
And
Figure FDA0002881760010000019
the included angle is between-5 degrees and 35 degrees;
(5) line voltage vector of PT secondary line of I-section bus
Figure FDA00028817600100000110
And
Figure FDA00028817600100000111
the included angle is between-5 degrees and 35 degrees;
(6) the load end breaker 1DL of line 1 is in the on position;
when the conditions are all met, a phase B disconnection signal of a No. 1 power supply incoming line circuit is sent out after a delay t 2;
3) control method for C-phase broken line identification
(1) Line voltage value U of PT secondary AB line of I-section busA2B2Greater than or equal to 0.9Eab1.1E or lessab；
(2) Line voltage value U of secondary BC line of PT (potential transformer) of I-section busB2C2Greater than or equal to 0.45Eab0.635E or lessab；
(3) Line voltage value U of PT secondary CA of I-section busC2A2Greater than or equal to 0.45Eab0.635E or lessab；
(4) Line voltage vector of PT secondary line of I-section bus
Figure FDA00028817600100000112
And
Figure FDA00028817600100000113
the included angle is between-5 degrees and 35 degrees;
(5) line voltage vector of PT secondary line of I-section bus
Figure FDA00028817600100000114
And
Figure FDA00028817600100000115
the included angle is between-5 degrees and 35 degrees;
(6) the load end breaker 1DL of line 1 is in the on position;
when the conditions are all met, a phase C disconnection signal of a No. 1 power supply incoming line circuit is sent out after a delay t 2;
method for identifying each phase disconnection of No. 1.22 power supply incoming line circuit
Acquiring secondary AB line voltage of II-section bus PT of load-end transformer substation
Figure FDA0002881760010000021
BC line voltage
Figure FDA0002881760010000022
CA line voltage
Figure FDA0002881760010000023
1) A-phase broken line identification method
(1) II section bus PT secondary AB line voltage value UA2B2Greater than or equal to 0.45Eab0.635E or lessab；
(2) II-section bus PT secondary BC line voltage value UB2C2Greater than or equal to 0.9Eab1.1E or lessab；
(3) II-section bus PT secondary CA line voltage value UC2A2Greater than or equal to 0.45Eab0.635E or lessab；
(4) II-section bus PT secondary line voltage vector
Figure FDA0002881760010000024
And
Figure FDA0002881760010000025
the included angle is between-5 degrees and 35 degrees;
(5) II-section bus PT secondary line voltage vector
Figure FDA0002881760010000026
And
Figure FDA0002881760010000027
the included angle is between-5 degrees and 35 degrees;
(6) the load side breaker 2DL of line No. 2 is in the on position;
when the conditions are all met, a phase disconnection signal of a No. 2 power supply incoming line circuit A is sent out after a delay t 1;
2) control method for B-phase broken line identification
(1) II section bus PT secondary AB line voltage value UA2B2Greater than or equal to 0.45Eab0.635E or lessab；
(2) II-section bus PT secondary BC line voltage value UB2C2Greater than or equal to 0.45Eab0.635E or lessab；
(3) II-section bus PT secondary CA line voltage value UC2A2Greater than or equal to 0.9Eab1.1E or lessab；
(4) II-section bus PT secondary line voltage vector
Figure FDA0002881760010000028
And
Figure FDA0002881760010000029
the included angle is between-5 degrees and 35 degrees;
(5) II-section bus PT secondary line voltage vector
Figure FDA00028817600100000210
And
Figure FDA00028817600100000211
the included angle is between-5 degrees and 35 degrees;
(6) the load side breaker 2DL of line No. 2 is in the on position;
when the conditions are all met, a No. 2 power supply incoming line B phase disconnection signal of the 35kV line is sent out after time delay t 1;
3) c-phase broken line identification method
(1) II section bus PT secondary AB line voltage value UA2B2Greater than or equal to 0.9Eab1.1E or lessab；
(2) II-section bus PT secondary BC line voltage value UB2C2Greater than or equal to 0.45Eab0.635E or lessab；
(3) II-section bus PT secondary CA line voltage value UC2A2Greater than or equal to 0.45Eab0.635E or lessab；
(4) II-section bus PT secondary line voltage vector
Figure FDA00028817600100000212
And
Figure FDA00028817600100000213
the included angle is between-5 degrees and 35 degrees;
(5) II-section bus PT secondary line voltage vector
Figure FDA00028817600100000214
And
Figure FDA00028817600100000215
the included angle is between-5 degrees and 35 degrees;
(6) the load side breaker 2DL of line No. 2 is in the on position;
when the conditions are all met, a phase C disconnection signal of a No. 2 power supply incoming line circuit is sent out after a delay t 1;
judging the condition of starting the circuit breaking to trip the circuit breaker at the power supply side or the load side and recovering the power supply by the spare power automatic switch
2.1 conditions for judging No. 1 line disconnection and No. 1 line jumping on load end breaker 1DL and switching on standby power supply breaker 2DL or 3DL by load end standby power automatic switching
If any one of the A-phase disconnection identification method, the B-phase disconnection identification method and the C-phase disconnection identification method in the 1 # power inlet line disconnection identification methods is met, identifying and judging that the 1 # power line is disconnected, performing disconnection protection in load end substation line protection, and starting a far jump 1 # power line power supply side circuit breaker 4DL through line optical fiber differential protection; because the No. 1 power supply circuit loses the power supply, the load end circuit breaker 1DL for jumping out the No. 1 circuit is started by the load end substation spare power automatic switching action, the spare power supply circuit breaker 2DL or 3DL is closed, or the disconnection protection in the load end substation No. 1 circuit protection, because the No. 1 power supply circuit loses the power supply, the load end substation spare power automatic switching action starts the closed spare power supply circuit breaker 2DL or 3DL, the transformer losing the power supply is recovered to the spare power supply circuit for supplying power, and the No. 1 circuit disconnection alarm is started at the same time;
2.2 conditions for judging No. 2 line disconnection jumping No. 2 disconnection line power supply side circuit breaker 5DL or No. 2 line load end circuit breaker 2DL and switching standby power supply circuit breaker 1DL or 3DL by load end standby power automatic switching start
If any one of the method for identifying phase A disconnection, the method for identifying phase B disconnection and the method for identifying phase C disconnection in the method for identifying the phase 2 power incoming line is satisfied, identifying and judging that the phase 2 power incoming line is disconnected, protecting the disconnection in the load-side substation line protection, and starting a far-jump phase 2 power line power-side circuit breaker 5DL through line optical fiber differential protection; as the No. 2 power supply circuit loses power supply, the load end substation spare power automatic switching action starts to trip off the load end circuit breaker 2DL of the No. 2 circuit, and closes the standby power supply circuit breaker 1DL or 3DL, or the disconnection protection in the No. 2 circuit protection of the load end substation trips the load end circuit breaker 2DL of the No. 2 circuit; 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 measuring the disconnection relay protection of the load side bus line voltage matched with the backup power automatic switching device according to 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 or a low-resistance grounding system.
3. The method for measuring the line voltage of the load side bus and the line break relay protection method matched with the automatic backup power switch as claimed in claim 1, wherein the value Eab of the secondary side rated line voltage of PT is 100V.
4. The method for measuring the line break relay protection by matching the load side bus line voltage with the automatic bus transfer equipment as claimed in claim 1, wherein t1 is 0.1-0.2 seconds when the three phases are not in phase when the breaker is closed; t2 is taken to be 5-7 seconds.
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