CN104319871B - Transformer station domain island protection and backup automatic switching integrated method - Google Patents

Abstract

The invention relates to a transformer station domain island protection and backup automatic switching integrated method. The method is characterized by comprising the following steps: (1), acquiring the electrical amount information and switch state information at the high voltage side, the intermediate voltage side and the low voltage side of a transformer station in real time, and according to whether backup automatic switching upkeep pressure plates are thrown or retreat, identifying the current running states of elements at the high voltage side, the intermediate voltage side and the low voltage side of the transformer station; and (2), according to actual wiring conditions and onsite operation demands, through apparatus function pressure plates, selecting whether the backup automatic switching functions and island protection functions of the high voltage side, the intermediate voltage side and the low voltage side are open; and through apparatus software control words, setting backup switching modes of the high voltage side, the intermediate voltage side and the low voltage side for coupling to the previously identified operation states of the elements at the high voltage side, the intermediate voltage side and the low voltage side of the transformer station, and if coupling fails, sending alarm signals, locking an apparatus and discharging. The method firstly has an island protection function, can rapidly detect an island state and an island scope existing in the transformer station, and jumps away from photovoltaic power station grid connected switches in the corresponding scope.

Description

A method for integration of substation domain anti-islanding protection and standby automatic switching

technical field

The invention relates to a method for integrating anti-islanding protection and standby automatic switching in a substation domain.

Background technique

As the load increases and a large number of photovoltaic power sources are connected to the substation, the operational reliability of the substation is becoming more and more important. After the photovoltaic power supply is connected to the substation, once the main power supply of the substation is disconnected and the substation is in an island state, the existence of the photovoltaic power station will cause a high residual voltage on the busbar of the substation, making the operation of the backup self-injection device unable to operate reliably, which will eventually cause the substation A total power outage. Therefore, how to quickly detect the island state on the substation side and cut off the grid-connected switch of the photovoltaic power station has become the key to improving the reliability of the power supply of the substation.

At the same time, the traditional standby self-switching equipment is designed based on the same voltage level, and can only realize the backup switch function at the same voltage level. Adding a backup automatic switching device on the medium and low voltage sides not only increases the investment cost and management difficulty of the substation, but also has some special problems even if multiple backup automatic switching devices are configured, such as the high-voltage incoming circuit breaker Refusal to move, or failure of the high-voltage side protection dead zone, will lead to the failure of the original high-voltage incoming line standby automatic switching scheme, resulting in a power outage in the entire substation.

Contents of the invention

The purpose of the present invention is to provide a substation domain anti-islanding protection and backup self-switching integration method, which can meet the requirements of 110kV substation for anti-islanding and multi-level backup self-switching, and can also solve the problem of incoming busbar refusal and protection dead zone The fault causes the problem of total shutdown of the substation, thereby preventing the total shutdown of the substation to the greatest extent.

A substation domain anti-islanding protection and integrated method for backup and automatic switching, which is special in that it includes the following steps:

(1) Real-time collection of electrical quantity information and switch status information on the high, medium, and low voltage sides of the substation, combined with whether the standby self-injection maintenance pressure plate is put in or out, to identify the current operating status of the high, medium, and low voltage side components of the substation;

(2) According to the actual wiring situation and on-site operation requirements, select whether the standby automatic switching function of the high, medium and low voltage side and the anti-islanding protection are open through the (standby automatic switch) device function pressure plate; through the (standby automatic switch) device software control Set the high, medium and low voltage side standby switching mode, and match the previously identified high, medium and low voltage side components' operating status, if not, send an alarm signal, (preparation automatic switching) device blocking discharge; when high The standby switching function and the anti-islanding protection function of the low, medium and low voltage sides are all enabled, and the backup switching modes of the high, medium and low voltage sides all match the identified status, then proceed to the next step, otherwise, repeat step (2);

(3) Detect whether the standby automatic switch meets the charging conditions, that is, when the standby automatic switch function and the anti-islanding protection function of the high, medium and low voltage sides are all open, it is necessary to start charging the device when all three sides meet the charging conditions, otherwise, repeat step (3);

(4) After the charging of the standby automatic switch is completed, if the anti-islanding protection function pressure plate is activated, it will first enter the island protection process, otherwise it will directly enter step (5) to start the logical judgment process of the standby automatic switch;

(5) Enter the start-up logic judgment of the standby automatic _{switching system. Specifically, first judge whether the high-voltage side bus is out of voltage. If the high-voltage side bus voltage U<U min represents} the minimum voltage value, the bus is judged to be out of voltage, and directly enters the step ( 6) The improved high-voltage side incoming line preparation self-switching action process;

(6) When the busbar on the high-voltage side loses pressure, enter the logical process of improving the incoming line backup on the high-voltage side. Specifically, first determine the location of the high-voltage fault. It is enough to restore the power supply to the line; if the fault occurs in a dead zone or it is impossible to confirm whether the incoming line circuit breaker is disconnected, first jump the high-voltage bus tie switch and the switch on the middle and low voltage side of the main transformer connected to the same bus as the main supply line to shut down the faulty area. After isolation, close the standby line switch and the bus tie switch on the medium and low voltage side to restore the power supply of the substation.

The electrical quantity information described in step (1) includes: single voltage and three-phase current of non-busbar components, two sets of line voltage signals of busbar components; switch status information includes HWJ and KKJ signals of circuit breakers; component operating status is divided into Line, bus coupler and busbar three types of component status, among which, the line status is divided into four types: maintenance, operation, ready for commissioning, and out of service; bus coupler status is divided into four types: running, overhaul, ready for commissioning and out of service; There are three corresponding states of the busbar: inspection, operation and outage.

The setting of the software control word for standby automatic switching in step (2) is used to set the standby switching mode of each side, and the setting principles of the soft control word for standby switching on the high, medium and low voltage sides are the same.

The matching of the operating state in step (2) specifically refers to checking whether the input function is consistent with the operating state of the substation.

The charging conditions described in the step (3) specifically include:

1) The charging conditions of the incoming line backup on the high-voltage side are: "High-voltage backup self-switching function pressure plate" is in the input state; the soft control word of the high-voltage backup switch is the incoming line backup; A group of line voltage > Uyy, the Uyy represents a fixed voltage value; the backup line must also meet the following conditions: the switch HWJ is a sub-position; the voltage of the backup line 2 > Uyy, the Uyy represents a fixed value; corresponding maintenance The pressure plate is in the exit state; the corresponding KKJ is closed and the input is 0. When the above conditions are all in the logical relationship of "and", the charging condition is met;

2) The charging conditions for the bus tie backup switch on the medium and low voltage side are: the "medium and low voltage backup self-switching function pressure plate" is in the input state; the medium and low backup switch soft control words are turned on; The sub-section switch is in the sub-position, and the corresponding KKJ is closed and the input is 0; both the middle and low sections of the busbar meet any phase voltage > Uyy, and the Uyy represents a fixed voltage value; when the above conditions are all in the logical relationship of "and" , which satisfies the charging condition.

The island protection process in step (4) specifically refers to judging whether there is an island based on the on-off status of the switches on each side. The specific logical relationship is as follows:

110kV bus bar judging and anti-islanding protection function: when the running main supply line switch trips, the 110kV bus bar meets the islanding judging condition; the device moves according to the outlet configuration control word to cut off the new energy grid-connected switch;

35kVI, II mother judgment anti-islanding protection function: under the premise of judgment 35kVI, II mother operation, any of the following conditions are met, 35kVI, II mothers meet the islanding discrimination condition, the device action follows the exit configuration control word to cut off the new energy grid connection switch;

1) When the 35kV bus tie switch is disconnected, the #1 and #2 main transformers become high or the switches of the transformers trip off;

2) The 35kV bus tie switch is closed, and the #1 and #2 main transformers become high or the mid-transformer switch trips;

3) The 35kV bus tie switch is closed, the #1 and #2 main transformer maintenance pressure plates are turned on, and the #2 and #1 main transformers are switched to high or mid-transformer switches;

4) The 35kV bus tie switch is closed, the #2 and #1 main transformer maintenance pressure plates are turned on, and the #1 and #2 main transformers are switched to high or mid-transformer switches;

The logic of the anti-islanding protection function of 10kVI and II mother judgments is consistent with the above-mentioned 35kVI and II mother judgment anti-islanding protection logic.

The high-voltage side fault location discrimination in the step (6) specifically refers to judging the fault area by detecting the incoming line and bus tie switch fault current direction, if the incoming line fault current points to the line, then the fault occurs on the line; if the incoming line fault If the current points to the busbar, the fault occurs on the busbar or between the incoming CT and the busbar; if there is no fault current on the busbar CT, the fault occurs on the busbar connected to the main supply incoming line; incoming bus.

In step (5), when the high-voltage side bus does not lose pressure, but only the medium and low voltage buses lose pressure, enter the medium and low voltage operation process.

The present invention provides an integrated method of station area anti-islanding protection and standby self-injection based on the same device. The method first has the function of anti-islanding protection, and can quickly detect the state and range of isolated islands in the substation, and jump out Photovoltaic power station grid-connected switch within the corresponding range; secondly, it can flexibly select the standby automatic switching function within the range of each voltage level; finally, for the special problems of the high-voltage side, the logic of the standby automatic switching operation of the incoming line at the high-voltage side is improved, and the multi-level switch Actions to complete the conversion of the power supply mode of the substation and prevent the substation from being completely shut down.

Description of drawings

Fig. 1 is the overall logic flow chart of the central station domain anti-islanding protection and backup self-switching of the present invention;

Fig. 2 is the logic diagram of the improved high-voltage side incoming line backup of the present invention;

Fig. 3 is a logic diagram for judging the line running state of the present invention;

Fig. 4 is the judging logic diagram of bus coupler running state of the present invention;

Fig. 5 is the judging logic diagram of bus running state of the present invention;

Fig. 6 is a logic diagram for judging the position of the fault point on the high voltage side of the present invention;

Fig. 7 is a block diagram of the overall structure of the present invention;

Fig. 8 is a wiring diagram of a typical 110kV substation with photovoltaic access to which the present invention is adapted.

detailed description

The present invention provides a substation domain anti-islanding protection and backup self-switching integration method, the method flow is shown in Figure 1, including the following steps:

(1) Real-time collection of electrical quantity information and switch status information on the high, medium and low voltage sides of the substation, combined with whether the self-initial maintenance pressure plate is put in or out, to identify the current operating status of the high, medium and low voltage side components of the substation;

(2) According to the actual wiring situation and on-site operation requirements, through the function plate of the device, select the standby automatic switching function of the high, medium and low voltage side and whether the anti-islanding protection is open; set the high, medium and low voltage side backup through the device software control word and match the operating status of the high, medium and low voltage side components previously identified. If they do not match, an alarm signal will be sent, and the device will be blocked and discharged; if the standby switching function and anti-islanding protection function of the high, medium and low voltage Open, the backup mode of the high, medium and low voltage sides must match the identified status before proceeding to the next step, otherwise, repeat step (2);

(3) Check whether the standby automatic switch meets the charging conditions. If the standby automatic switch function and the anti-islanding protection function of the high, medium and low voltage sides are all open, then the three sides need to meet the charging conditions before starting to charge the device. Otherwise, repeat the steps (3);

(4) After the standby auto-injection charging is completed, if the anti-islanding protection function pressure plate is activated, it will enter the island protection process first, otherwise it will directly enter step (5) to start the logical judgment of the standby auto-injection;

(5) Enter the start-up logic judgment of standby automatic switching system, among which first judge whether the high-voltage side bus is out of voltage. If the high-voltage side bus voltage U<U _min , the U _min represents the minimum voltage value, which can be determined according to conventional theoretical calculation or actual experience. Then it is judged that the busbar loses pressure, and directly enters the action process of improving the high-voltage side incoming line standby automatic switchover in step (6); if the high-voltage side busbar does not lose pressure, but only the medium and low voltage buses lose pressure, then enter the medium and low voltage action process , the action process of the medium and low voltage side is consistent with the normal standby automatic switching action, which will not be described in this article;

(6) When the busbar on the high-voltage side loses pressure, enter the logical process of improving the incoming line backup on the high-voltage side. Specifically, first determine the location of the high-voltage fault. It is enough to restore the power supply to the line; if the fault occurs in a dead zone or it is impossible to confirm whether the incoming line circuit breaker is disconnected, first jump the high-voltage bus tie switch and the switch on the middle and low voltage side of the main transformer connected to the same bus as the main supply line to shut down the faulty area. After isolation, the standby line switch and the bus tie switch on the medium and low voltage sides are combined to restore the power supply of the substation.

The electrical quantity information described in step (1) includes: single voltage and three-phase current of non-busbar components, two sets of line voltage signals of busbar components; switch status information includes HWJ and KKJ signals of circuit breakers; component operating status is divided into line , bus coupler and busbar three types of component status, among which, the line status is divided into four types: maintenance, operation, ready for commissioning, and outage, and the corresponding logic judgment process is shown in Figure 3; The corresponding logical judgment flow for maintenance, standby operation and outage is shown in Figure 4; the corresponding status of the bus is divided into three types: maintenance, operation and outage, and the corresponding logic flow is shown in Figure 5.

The setting of the backup automatic switching software control word in step (2) is used to set the backup switching mode of each side. Among them, the setting principle of the soft control words of the high, medium and low voltage sides is the same. Taking the high voltage side as an example, when the high voltage side is switched on, if the two busbars run in parallel and there is a backup line, the incoming line of the high voltage side should be switched. If it is set to 1, the bus tie backup switch on the high-voltage side should be set to 0; if the two buses are running separately, the high-voltage side incoming line backup switch is 0, and the bus tie backup switch is 1; if the high-voltage backup switch function pressure plate exits, The setting of the backup soft control word is invalid.

The state matching described in step (2) is used to check whether the input function is consistent with the operating state of the substation, which corresponds to the following table 1:

Table 1 Functional platen and detection state matching table

The charging conditions described in the step (3) specifically include:

1) The switching and charging conditions of the incoming line backup on the high-voltage side are: the "high-voltage backup self-switching function pressure plate" is in the switched-on state; the soft control word of the high-voltage backup switching is the incoming line backup; A set of line voltage > Uyy (with fixed value); the backup line must meet the following conditions at the same time: the switch HWJ is divided; the voltage of backup line 2 > Uyy (with fixed value). ③ The corresponding maintenance pressure plate is exiting Status; the corresponding KKJ is closed and the input is 0. The above conditions are all in the logical relationship of "and" to meet the charging conditions.

2) The charging conditions for the bus tie backup switch on the medium and low voltage side are: the "medium and low voltage backup self-switching function pressure plate" is in the input state; the medium and low backup switch soft control words are turned on; (Segmentation) The switch is in the sub-position, and the input is 0 after the corresponding KKJ is closed; both the middle and low sections of the busbar meet any phase voltage > Uyy (voltage fixed value); the above conditions are all logical relations of "and", to meet the charging conditions.

The island protection process in step (4) specifically refers to judging whether there is an island based on the off-state of the switches on each side. The specific logical relationship is as follows:

110kV bus bar judging and anti-islanding protection function: when the running main supply line switch trips, the 110kV bus bar meets the islanding judging condition; the device moves according to the outlet configuration control word to cut off the new energy grid-connected switch;

35kVI (II) mother judging anti-islanding protection function: under the premise of judging the 35kVI (II) mother running, if any of the following conditions are met, the 35kVI (II) mother meets the islanding judgment condition, and the device will act according to the export configuration control word cut off the new Energy grid connection switch.

1) When the 35kV bus tie switch is disconnected, the #1 (#2) main transformer becomes high or the switch of the transformer trips;

2) The 35kV bus tie switch is closed, and the #1 and #2 main transformers become high or the mid-transformer switch trips;

3) The 35kV bus tie switch is closed, the #1 (#2) main transformer maintenance pressure plate is turned on, and the #2 (#1) main transformer becomes high or the middle switch of the transformer trips;

4) The 35kV bus tie switch is closed, the #2 (#1) main transformer maintenance pressure plate is turned on, and the #1 (#2) main transformer becomes high or the middle switch of the transformer trips.

The logic of the anti-islanding protection function of the 10kVI (II) mother switch is consistent with the logic of the 35kVI (II) mother switch anti-islanding protection function, and the description will not be repeated.

The high-voltage side fault location discrimination in the step (6) specifically refers to judging the fault area by detecting the incoming line and bus tie switch fault current direction, if the incoming line fault current points to the line, then the fault occurs on the line; if the incoming line fault If the current points to the busbar, the fault occurs on the busbar or between the incoming CT and the busbar; if there is no fault current on the busbar CT, the fault occurs on the busbar connected to the main supply incoming line; incoming bus. The specific process of high-voltage side fault discrimination is shown in Figure 6 below.

The overall process for realizing the method of the present invention includes four major (functional) modules: a state monitoring and function matching module, a charging module, an anti-islanding protection module, and a standby automatic switching action module. Their relationship is shown in Figure 7.

Example 1:

Figure 8 is a typical wiring diagram of a 110kV substation. The scheme will be described in detail below in conjunction with the wiring method in Figure 8.

Firstly, the electric quantity and the switch quantity signal are collected. Due to the large number of signals collected by the device, considering the limited AC and switching quantities connected to the device, single voltage and three-phase current are selected for non-bus components, and two sets of line voltage signals are selected for bus components; and each circuit breaker needs to adopt HWJ and KKJ signal.

Table 2 Information Collection Form

collected components Collected analog Switch 110kV incoming line 1 and circuit breaker 111 Ua, Ia, Ib, Ic HWJ, KKJ 110kV incoming line 2 and circuit breaker 112 Ua, Ia, Ib, Ic HWJ, KKJ 110kV Bus Tie and Circuit Breaker 110 Ia, Ib, Ic HWJ, KKJ 110kV busbar Ⅰ and circuit breaker 101 Uab, Ubc HWJ, KKJ 110kV busbar II and circuit breaker 102 Uab, Ubc HWJ, KKJ 1# main transformer 35kV side and circuit breaker 301 Ua, Ia, Ib, Ic HWJ, KKJ 2# main transformer 35kV side and circuit breaker 302 Ua, Ia, Ib, Ic HWJ, KKJ 35kV bus tie and circuit breaker 300 Ia, Ib, Ic HWJ, KKJ 35kV busbar Ⅰ Uab, Ubc 35kV Bus II Uab, Ubc 1# main transformer 10kV side and circuit breaker 501 Ua, Ia, Ib, Ic HWJ, KKJ 2# main transformer 10kV side and circuit breaker 502 Ua, Ia, Ib, Ic HWJ, KKJ 10kV bus tie and circuit breaker 500 Ia, Ib, Ic HWJ, KKJ 10kV busbar Ⅰ Uab, Ubc 10kV Bus II Uab, Ubc

Component operating status identification is divided into line status identification, bus status identification, and bus coupler status identification. Line status is divided into four types: inspection, operation, backup and shutdown, and its logic judgment process is shown in Figure 3; bus coupler status is divided into four types: operation, inspection, backup and shutdown, and its corresponding logic The judgment process is shown in Figure 4; the corresponding status of the bus is divided into three types: maintenance, operation and outage, and its corresponding logic flow is shown in Figure 5.

Read the standby switching function pressure plate and the soft control word of the standby switching mode, and match it with the identified operating mode. If the matching is successful, go to the next step. Table 3 gives the corresponding matching table.

Table 3 Functional pressure plate and detection status matching table

When the device enters the charging process, it is necessary to judge the charging logic of the incoming line according to the selected standby auto-input function:

The switching and charging conditions of the high-voltage side incoming equipment are as follows:

"High voltage standby self-switching function pressure plate" is in the switching state;

The soft control word for high-voltage standby switching is incoming line standby switching

The bus tie switch is in close position;

The two sections of busbars all meet the requirement that any set of line voltages > Uyy (voltage-set value);

The backup line must meet the following conditions at the same time:

①The switch HWJ is the minute;

②Voltage of backup line 2>Uyy (with voltage setting).

③The corresponding maintenance platen is in exit state;

④The corresponding KKJ is closed and the input is 0.

The charging conditions for the bus tie backup switch on the medium and low voltage side are:

The "medium and low voltage backup self-switching function pressure plate" is in the switching state;

Medium and low backup soft control word inputs

The medium and low bus coupler maintenance pressure plate is withdrawn and the bus coupler (section) switch is in the position, and the corresponding KKJ is closed and the input is 0;

The middle and low sections of busbars all meet the voltage of any phase > Uyy (voltage fixed value);

If the device selects the backup function of opening the high, medium and low voltage sides, all three sides need to meet the charging conditions. When the conditions are all satisfied, after the Tc time delay, enter the charging completion state of the device.

After charging is complete, if the anti-islanding protection function is enabled, it will enter the anti-islanding protection process. Judgment The anti-islanding protection is judged by the switches on each side. The specific logic relationship is as follows:

110kV busbar anti-islanding protection function:

When the switch of the running main supply line trips, the 110kV bus meets the islanding criteria; the action of the device is to cut off the new energy grid-connected switches 311, 312, 511, and 512 according to the export configuration control word.

35(10)kVI mother judgment anti-islanding protection function:

Under the premise of judging the operation of the 35(10)kVI bus, if any of the following conditions is met, the 35(10)kVI bus will meet the islanding discrimination condition, and the device will act according to the outlet configuration control word to cut off the new energy grid-connected switch 311 (511).

1) When the 35 (10) kV bus tie switch is disconnected, the #1 main transformer becomes high or the switch of the transformer trips;

2) The 35(10)kV bus tie switch is closed, the #1 and #2 main transformers become high or the mid-transformer switch trips;

3) The 35 (10) kV bus tie switch is closed, the #1 main transformer maintenance pressure plate is turned on, and the #2 main transformer is turned high or the middle switch is tripped;

4) The 35 (10) kV bus tie switch is closed, the #2 main transformer inspection pressure plate is turned on, and the #1 main transformer is turned high or the middle switch of the transformer is tripped.

●35(10)kVII mother judgment anti-islanding protection function:

When judging that the 35(10)kVII bus is running ahead of schedule, any of the following conditions is met, and the 35(10)kVII bus meets the islanding discrimination condition, and the device acts to cut off the new energy grid-connected switch 312 (512) according to the outlet configuration control word.

1) When the 35 (10) kV bus tie switch is disconnected, the #2 main transformer becomes high or the switch of the transformer trips;

2) The 35(10)kV bus tie switch is closed, and the #1 and #2 main transformers become high or the transformer switch trips;

3) The 35 (10) kV bus tie switch is closed, the #2 main transformer maintenance pressure plate is turned on, and the #1 main transformer becomes high or the middle switch of the transformer trips;

4) The 35 (10) kV bus tie switch is closed, the #1 main transformer inspection pressure plate is turned on, and the #2 main transformer is turned high or the middle switch of the transformer is tripped.

After the anti-islanding protection module is completed, it enters the logical judgment of standby auto-startup.

When it detects the loss of voltage on the high-voltage side, the standby automatic switching device immediately enters the logic of the high-voltage side standby automatic switching; action logic.

When the high-voltage side loses voltage and enters the high-voltage backup logic, it first detects whether there is voltage in the backup supply line, and if there is no voltage in the backup supply line, the device discharges; The direction of the fault current of the line and bus tie switch is used to judge the fault area. If the fault current of the incoming line points to the line, the fault occurs on the line; if the fault current of the incoming line points to the bus bar, the fault occurs on the bus bar or between the incoming line CT and the bus bar; If there is no fault current on the bus tie CT, the fault occurs on the bus connected to the main supply incoming line, otherwise, the fault occurs on the bus connected to the backup supply incoming line. The specific process of high-voltage side fault discrimination is shown in Figure 6 below.

If the fault occurs on the main supply line, it is only necessary to follow the conventional incoming line backup self-switching logic, and then close the switch of the backup supply line after confirming that the main supply line is tripped; but if the fault occurs on the protection incoming line CT and circuit breaker In between, or the main supply circuit breaker refuses to operate, or if the fault occurs on the I bus, the fault isolation is formed by tripping the high-voltage bus tie switch and the medium and low-voltage side switches of the transformer connected to the I bus, and then the power supply line is combined The switch restores the power supply of the II bus, and finally closes the medium and low voltage bus tie switches to restore the power supply of the whole station. But pay attention, if the fault occurs on the II bus, the standby power-on will be locked. Through the analysis, the improved high-voltage side backup self-switching mode has improved the reliability of the high-voltage side bus power supply, and greatly reduced the probability of power failure in the entire substation.

For 110kV substations with photovoltaic access, the present invention designs an integrated method with station area anti-islanding protection and standby automatic switching functions, and collects relevant electrical quantities and data of high, medium and low voltage sides of 110kV substations in one standby automatic switching device The position information of the circuit breaker judges the operating status of the system; the anti-islanding protection function and whether the high, medium, and low side standby automatic switching functions are enabled or not can be selected through the function pressure plate or soft control word; before the standby automatic switching logic starts, it is necessary to perform anti-islanding Protection judgment logic, if there is an island within the scope of the substation, it is necessary to cut off the grid-connected switch of the photovoltaic power station first; in this method, the original high-voltage side incoming line standby automatic switching action logic is also improved to realize high, medium and low side circuit breakers Orderly cooperation to solve the problem of power outage in the substation when the incoming line refuses to move or the dead zone fails.

The above description only expresses one embodiment of the present invention, and its description is relatively specific and detailed, but it can therefore be understood as a limitation of the patent scope of the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the solution, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (8)

1. A substation domain anti-islanding protection and standby self-switching integration method is characterized in that, comprising the following steps: (1) Real-time collection of electrical quantity information and switch status information on the high, medium, and low voltage sides of the substation, combined with whether the standby self-injection maintenance pressure plate is put in or out, to identify the current operating status of the high, medium, and low voltage side components of the substation; (2) According to the actual wiring situation and on-site operation requirements, through the function plate of the standby automatic switching device, select whether the standby automatic switching function of the high, medium and low voltage side and the anti-islanding protection are open; set the high , medium and low voltage side standby switching mode, and match the operating status of the previously identified high, medium and low voltage side components. The backup function and the anti-islanding protection function are all enabled, and the backup mode of the high, medium and low voltage sides all match the identified status, then proceed to the next step, otherwise, repeat step (2); (3) Detect whether the backup auto-injection device meets the charging conditions, that is, when the backup auto-injection function and the anti-islanding protection function of the high, medium and low voltage sides are all open, the three sides need to meet the charging conditions before starting to charge the backup auto-injection device , otherwise, repeat step (3); (4) After the charging of the standby automatic switching device is completed, if the anti-islanding protection function pressure plate is put into operation, it will first enter the island protection process, otherwise it will directly enter step (5), that is, the logical judgment process of the standby automatic switching start; (5) Enter the start-up logic judgment of the standby automatic _{switching system. Specifically, first judge whether the high-voltage side bus is out of voltage. If the high-voltage side bus voltage U<U min represents} the minimum voltage value, the bus is judged to be out of voltage, and directly enters the step ( 6) The improved high-voltage side incoming line preparation self-switching action process; (6) When the high-voltage side bus loses pressure, enter the logic process of improving the high-voltage side incoming line standby self-switching. Specifically, first determine the location of the high-voltage fault. It is enough to restore the power supply to the line; if the fault occurs in a dead zone or it is impossible to confirm whether the incoming line circuit breaker is disconnected, first jump the high-voltage bus tie switch and the main transformer medium and low-voltage side switches connected to the same bus as the main supply line to close the fault area. After isolation, close the standby line switch and the bus tie switch on the medium and low voltage side to restore the power supply of the substation. 2. A kind of substation domain anti-islanding protection and backup self-switching integration method as claimed in claim 1, characterized in that: the electrical quantity information described in step (1) includes: single voltage and three voltages of non-bus components Phase current, two sets of line-to-line voltage signals of bus components; switch status information includes HWJ and KKJ signals of circuit breakers; component operation status is divided into three types of component states: line, bus coupler and bus bar. Among them, the line status is divided into four types: maintenance , running, ready for commissioning, and out of service; there are four bus coupler states: running, overhaul, ready for commissioning, and out of service; there are three corresponding busbar states: overhaul, running, and out of service. 3. A kind of substation domain anti-islanding protection and backup self-switching integration method as claimed in claim 1, characterized in that: the backup self-switching software control word setting in step (2) is used to set the backup of each side The setting principles of the soft control word of the high, medium and low voltage side standby switching are the same. 4. A kind of substation domain anti-islanding protection and standby self-switching integration method as claimed in claim 1, characterized in that: the operation state described in the step (2) is matched specifically refers to checking the input function and Whether the operating status of the substation is consistent. 5. A kind of substation domain anti-islanding protection and backup self-switching integration method as claimed in claim 1, characterized in that: the charging conditions described in step (3) specifically include: 1) The charging conditions of the incoming line backup on the high-voltage side are: "High-voltage backup self-switching function pressure plate" is in the input state; the soft control word of the high-voltage backup switch is the incoming line backup; A group of line voltage > Uyy, the Uyy represents a fixed voltage value; the backup line must also meet the following conditions: the switch HWJ is a sub-position; the voltage of the backup line 2 > Uyy, the Uyy represents a fixed value; corresponding maintenance The pressure plate is in the exit state; the corresponding KKJ is closed and the input is 0. When the above conditions are all in the logical relationship of "and", the charging condition is met; 2) The charging conditions for the bus tie backup switch on the medium and low voltage side are: the "medium and low voltage backup self-switching function pressure plate" is in the input state; the medium and low backup switch soft control words are turned on; The sub-section switch is in the sub-position, and the corresponding KKJ is closed and the input is 0; both the middle and low sections of the busbar meet any phase voltage > Uyy, and the Uyy represents a fixed voltage value; when the above conditions are all in the logical relationship of "and" , which satisfies the charging condition. 6. A kind of substation domain anti-islanding protection and standby self-switching integration method as claimed in claim 1, characterized in that: the islanding protection process in step (4) specifically refers to the detection of the islanding protection process through the off-state of the switches on each side. To determine whether there is an isolated island, the specific logical relationship is as follows: 110kV bus bar judging and anti-islanding protection function: when the running main supply line switch trips, the 110kV bus bar meets the islanding judging condition; the standby self-injection device operates and cuts off the new energy grid-connected switch according to the export configuration control word; Anti-islanding protection function for 35kVI and II bus: under the premise of judging the operation of 35kVI and II bus, if any of the following conditions is met, the 35kVI and II bus will meet the islanding discrimination condition, and the action of the standby automatic switching device will be cut according to the control word of the outlet configuration. Energy grid-connected switch; 1) When the 35kV bus tie switch is disconnected, the #1 and #2 main transformers become high or the switches of the transformers trip off; 2) The 35kV bus tie switch is closed, and the #1 and #2 main transformers become high or the mid-transformer switch trips; 3) The 35kV bus tie switch is closed, the #1 and #2 main transformer maintenance pressure plates are turned on, and the #2 and #1 main transformers are switched to high or mid-transformer switches; 4) The 35kV bus tie switch is closed, the #2 and #1 main transformer maintenance pressure plates are turned on, and the #1 and #2 main transformers are switched to high or mid-transformer switches; The logic of the anti-islanding protection function of 10kVI and II mother judgments is consistent with the logic of the above-mentioned 35kVI and II mother judgment anti-islanding protection. 7. A kind of substation domain anti-islanding protection and backup self-switching integration method as claimed in claim 1: the high-voltage side fault location discrimination in step (6) specifically refers to detecting incoming line and bus tie switch faults If the fault current of the incoming line points to the line, the fault occurs on the line; if the fault current of the incoming line points to the busbar, the fault occurs on the busbar or between the incoming line CT and the busbar; if there is no If the fault current occurs, the fault occurs on the busbar connected to the main supply incoming line, otherwise, the fault occurs on the busbar connected to the standby supply incoming line. 8. A substation domain anti-islanding protection and backup self-switching integrated method as claimed in claim 1: in step (5), when the high-voltage side busbar is not depressurized, but only the medium and low-voltage busbars are depressurized, enter Medium and low pressure action process.