CN104518564B - Backup automatic switching apparatus with area automatic switching function, and backup automatic switching method - Google Patents

Abstract

The invention discloses a backup self-switching device with the function of regional self-switching, which is used in a power supply system with a dual power supply serial supply structure; The device is installed in any power station or series power supply substation, and several collection and execution units are respectively installed in two power supply stations and each series supply substation, and all collection and execution units exchange real-time information with the regional standby self-injection device through the optical fiber communication network; Each acquisition and execution unit collects the analog quantity information of its corresponding station, converts it into a switch signal and sends it to the regional standby automatic switching device through the optical fiber communication network, and at the same time receives the tripping and closing command issued by the regional standby automatic switching device and executes the switching signal. Closing action. This kind of device can realize that when any string supply switch is used as an open-loop point, it can quickly restore power supply to the power-off string supply substation through a one-time tripping and closing operation. The invention also discloses a backup self-starting method of the standby automatic switch-on device with the function of regional automatic switch-on.

Description

A backup self-switching device with regional self-switching function and a backup self-switching method

technical field

The invention relates to an automatic switching device for power transmission and distribution in a power system, in particular to a microcomputer standby power automatic switching device and method.

Background technique

In recent years, standby automatic switching devices have been widely used in power grids of 220kV and below, and have played an important role in maintaining the stability of the power grid and improving the reliability of power supply.

If the standby automatic switching device is to function, there must be a backup power supply and a backup switch in a hot standby state. When the working power supply loses power, the backup self-switching device jumps off the switch of the original working power supply, closes the switch of the backup power supply, realizes the rapid and automatic input of the backup power supply, and restores the power supply for the substation. The backup switch in the hot standby state of the backup power supply is generally called an open-loop point. Only when there is an open-loop point, can the automatic switching of the backup power supply be realized. The dual power supply series supply structure is a common power supply structure in the 110kV power grid. Two power stations are used to supply power to several serially connected substations in the middle. In order to suppress the short-circuit current during closed-loop operation, open-loop operation is adopted, that is, open One of the series supply switches can indeed reduce the short-circuit current after open-loop operation, but each series supply substation is powered by a single power station, and the reliability of power supply is reduced. The station is used as a backup power supply, and the reliability of power supply is improved through automatic switching.

If the conventional standby automatic switching is used, only one of the substations has an open-loop point, and the other substations do not have an open-loop point. The substation without an open-loop point has no backup power switch to control, and the conventional standby automatic switching cannot be used. In this way, except for the substation where the open-loop point is located, other substations cannot work even if they are equipped with conventional automatic switching devices, and the purpose of quickly restoring power supply and improving power supply reliability cannot be achieved. For general remote standby automatic switching devices, only two substations can realize standby automatic switching, but it is not applicable to the common main wiring of multiple substations connected in series. For the regional standby self-switching function embedded in the EMS system, due to the large data transmission delay, it takes a long time to restore power supply. Some people have also proposed a regional backup self-switching strategy for step-by-step recovery. When the series power substation loses power, all the switches of the lost substation will be tripped, and then the power supply will be restored step by step. This method involves a large number of switching operations, and it takes a long time to restore the power supply, and there will be a certain impact on the system when the switch is closed on a fault. None of the above-mentioned methods can quickly and accurately restore power to the power-off substation.

Contents of the invention

The purpose of the present invention is to provide a backup self-switching device and a backup self-switching method with the function of regional self-switching, which is suitable for a dual power supply series supply structure, and can realize a single trip and close operation when any series supply switch is used as an open loop point The power supply can be quickly restored for the lost power series supply substation.

In order to achieve the above object, the solution of the present invention is:

A backup self-switching device with regional self-switching function, which is used in a power supply system with a dual power supply series supply structure, and the dual power supply series supply structure includes two power stations and at least two series supply substations; The self-injection device and several acquisition and execution units, the regional self-injection device is configured in any power station or series power substation, several acquisition and execution units are respectively set in two power stations and each series power substation, and all acquisition and The execution units exchange real-time information with the regional standby automatic switching device through the optical fiber communication network; the acquisition and execution units collect the analog information of their corresponding stations, convert it into a switch signal and send it to the regional standby automatic switching through the optical fiber communication network device, and at the same time receive the tripping and closing command issued by the regional standby automatic switching device and execute the tripping and closing action.

The above-mentioned power station adopts substation, busbar or tie-line power supply.

The acquisition and execution units corresponding to the above-mentioned stations are connected to the bus voltage of the station, and are converted into switching signals of the bus voltage sign and the bus no-voltage sign according to the set bus voltage and bus no-voltage values; The current of the two series supply incoming lines is converted into the switching signal of the incoming line fault current flag and the incoming line no-current flag according to the set incoming line fault current value and incoming line no-current value, and combined with the bus voltage to calculate The angle between the voltage and the current is used to obtain the direction mark of the current; the trip position contacts of the two series power switches are collected for the discrimination of the system operation mode; the closed position contacts of the two series power switches are collected for locking when the hand trips the working power supply Backup self-switching; collect the action signal of bus differential protection to identify bus faults; the acquisition and execution unit sends the above-mentioned flags and switches to the regional backup automatic switching device through the optical fiber communication network, and the regional backup automatic switching The device makes comprehensive decisions.

A kind of method based on the self-switching device with regional self-switching function as mentioned above, comprising the following steps:

(1) Regional standby self-switching adopts charging and discharging logic. When the system is operating normally, a certain string supply switch is used as an open loop point, and the rest of the string supply switches are closed for operation, and the bus voltage of each substation is under pressure. After charging and setting time, the regional backup automatic After the charging is completed, set the charging sign;

(2) After the charging of the regional standby automatic switching is completed, if the system has a fault or the power station loses voltage, the regional standby automatic switching device will select a series supply switch suitable for isolating the fault according to the fault situation;

(3) After the trip delay, issue a command to trip the previously selected series supply switch. The trip command is sent to the acquisition and execution unit of the corresponding substation through the optical fiber communication network to perform the trip action. After confirming that the series supply switch is tripped, the closing delay Issue the closing and opening loop point series supply switch command, and the closing command is sent to the acquisition and execution unit of the substation where the open loop point is located through the optical fiber communication network to implement the actual closing.

After adopting the above scheme, the beneficial effects of the present invention are: the position of the open-loop point of the self-adaptive dual power supply string supply structure, when any string supply switch is used as the open-loop point, the regional backup self-injection device can automatically identify; Select the appropriate series switch to trip to isolate the fault and prevent the switch from closing on the fault; make a decision based on the status of each substation, and can restore power to multiple power-off series substations at the same time, not limited to substations with open loop points; backup The automatic switching operation process only needs one tripping and closing operation, which is concise and accurate; no matter how many series supply substations, the regional backup automatic switching device can be applied; the real-time information is transmitted through the optical fiber communication network, and the regional backup covering multiple substations is truly realized. cast.

Description of drawings

Fig. 1 is a schematic diagram of the main wiring of the power supply system applied in the present invention;

Fig. 2 is the logic diagram of the self-injection of regional equipment of the present invention;

Fig. 3 is a schematic diagram of the automatic switching operation of the regional equipment in the present invention.

detailed description

The technical solutions of the present invention will be described in detail below in conjunction with the accompanying drawings.

The present invention provides a backup self-switching device with a regional self-switching function, which is suitable for a power supply system with a dual power supply serial supply structure, as shown in FIG. 1 . Power station 1 and power station 2 are two power stations. Station A, station B and station C are three series power supply substations. 001-008 are the switches for each series supply. Among them, 005 is the open-loop point under the current operation mode. The scale of the series power supply structure shown in this figure is only an example. When the number of series power substations and series power switches increases or decreases, the present invention is still applicable. The dual power sources in this figure are power station 1 and power source station 2 in form. For other forms of dual power sources, for example, bus I and bus II of the same substation are used as two power sources respectively, or one of the power sources is a tie line power source, or The two power supplies are all tie-line power supplies, and the present invention is still applicable.

Each substation (including power substation and series power substation) is equipped with an acquisition and execution unit respectively, and one of the substations is selected to configure a regional backup automatic input device, and the regional backup automatic input device interacts with each acquisition and execution unit through the optical fiber communication network in real time information. The analog quantities that need to be connected to each acquisition and execution unit include: the bus voltage of the station, the current of the 2 series supply incoming lines; the switch quantities that need to be connected include: the trip position and closed position of the 2 series supply switches, and the bus difference Protection action signal, self-switching and opening in the blocking area, etc. The acquisition and execution unit converts the collected analog quantity into a switch value sign, and converts the bus voltage into a bus voltage sign and a bus no-voltage sign according to the set bus voltage and bus no-voltage values; according to the set Incoming line fault current setting value, incoming line no-current setting value, the incoming line current is converted into the incoming line fault current mark, the incoming line no-current mark; use the bus voltage and incoming line current to calculate the angle between voltage and current, Get the sign of the direction of the current. The acquisition and execution unit sends the above-mentioned various flags and switches to the regional backup automatic input device through the optical fiber communication network, and the regional backup automatic input device makes comprehensive decisions.

The delay of information transmission through the optical fiber communication network can reach a level of less than 1 millisecond, and the acquisition and execution unit converts each analog quantity into a switch quantity through local criteria, and only exchanges the switch quantity information number with the regional backup automatic input device, so that The length of the transmission message is greatly reduced, which is conducive to the rapid transmission of information. In this case, the requirement of real-time interactive information can be met. By exchanging real-time information, the regional standby automatic switching device can achieve the same action time accuracy as the ordinary local standby automatic switching device, and the actual action time can reach the level of milliseconds. The same setting principles are considered. In this case, it is also possible to achieve equal cooperation with common standby automatic switching. For example, according to the general principle that the high-voltage side standby automatic switching takes precedence over the low-voltage side standby automatic switching, if this set of regional standby automatic switching is installed at a voltage level of 110kV , the action time of the regional standby automatic switching can be set according to the priority action; the operating time of the standby automatic switching with a voltage level below 110kV can be set to be greater than the action time of the regional standby automatic switching, and it can be exactly the same as the normal high-voltage side standby automatic switching. The setting principle.

The action logic reference of the regional standby self-injection device is shown in Figure 2. It mainly includes the following steps:

Step 1: Charge and discharge logic. The regional backup self-injection device adopts the charging and discharging logic, and only after the charging is completed, the backup and self-injection operation can be performed. When all the charging conditions are met, and no discharging conditions are met, the charging is completed after the charging setting time, and the charging flag is set.

The charging condition is an "and" relationship, and all charging conditions need to be met at the same time, and the charging is completed after the charging setting time. The charging conditions are:

1) Both power stations have three-phase voltage;

2) Each string supply substation has three-phase voltage;

3) A certain series supply switch is in the opening position, and other series supply switches are in the closing position, and all switches have no abnormal position alarm.

The discharge condition is an "or" relationship, if any discharge condition is met, it will be discharged and the charging mark will be cleared. The discharge conditions are:

1) The open loop point switch is closed;

2) After a short delay, the regional standby auto switch issues a closing command;

3) Remote jump, hand jump any running series supply switch (the closed position KKJ of the running series supply switch becomes 0);

4) The busbars of the two power stations are without voltage, and there is a delay in the no-voltage discharge of the backup power supply;

5) After the regional standby automatic switch sends a trip command, the corresponding series supply switch refuses to move;

6) The position of the series supply switch selected as the pre-trip switch is abnormal;

7) The information of the acquisition and execution sub-station of any substation cannot be received;

8) Any substation has a blocking area for automatic switching and external blocking input;

9) After receiving abnormal communication information from the collection and execution substation of a certain substation, the substation cannot receive the information of the regional backup automatic switching device. The substation where the ring point is located is not locked;

10) After the operation of the regional standby self-injection device, it needs to be manually confirmed before it can be charged again;

11) The busbar of the substation where the open-loop point is located is faulty, or the busbar of the station opposite to the open-loop point is faulty;

12) The line where the open loop point is located is faulty;

13) Faults occur on both sides of the open loop point;

14) Exit the function of self-injection of area backup.

Step 2: Fault identification and trip switch selection. After the charging is completed, if there is a fault in the system, the relay protection device will jump off a closed series switch, or the power station loses voltage and the series power substation loses power. It is used to isolate the faulty series supply switch to prevent the backup power switch from being mistakenly closed when the fault is closed.

Step 3: After locating the fault and selecting the trip switch, after the trip delay, issue a command to trip the selected series supply switch, and the acquisition and execution unit of the substation where the trip series supply switch is located performs the actual trip operation. The switch-on command of the series supply switch of the open-loop point is issued after the closing delay, and the acquisition and execution unit of the substation where the open-loop point is located performs the actual closing operation. After one trip and closing operation, the power supply of the power-off series supply substation can be restored.

According to the power supply system shown in Figure 1, and considering that there is a small power supply connected to the busbar of station C, when the system operates with the 005 switch as the open-loop point, consider the action of regional backup automatic switching under various fault locations, and refer to the location of the fault point image 3.

After the regional standby auto-charging is completed:

1) When a fault occurs at point K1 on line A, the regional backup self-injection jumps off the 002 switch to isolate the fault, and then closes the 005 switch to restore power supply to stations A and B.

2) When the K2 point fault occurs on the busbar of station A, the regional backup self-injection jumps off the 004 switch to isolate the fault, and then closes the 005 switch to restore power supply to B station.

3) When a fault occurs at point K3 on line B, the regional backup self-injection jumps off the 004 switch to isolate the fault, and then closes the 005 switch to restore power to station B.

4) When the K4 point fault occurs on the busbar of station B, the regional backup powers up automatically to prevent the switch from closing on the fault.

5) When a fault occurs at point K5 on line C, the regional backup powers up automatically to prevent the switch from closing on the fault.

6) When the K6 point fault occurs on the busbar of station C, the regional backup powers up automatically to prevent the switch from closing on the fault.

7) When a fault occurs at point K7 on the D line, the regional backup self-injection jumps off the 007 switch to isolate the fault, and then closes the 005 switch to restore power to station C.

8) Power station 1 loses voltage, and the regional backup self-injection jumps off the 002 switch, and then closes the 005 switch to restore power supply for stations A and B.

9) When the power station 2 loses voltage, the regional standby self-injection jumps off the 007 switch, and then closes the 005 switch to restore power to the C station.

The above embodiments are only to illustrate the technical ideas of the present invention, and can not limit the protection scope of the present invention with this. All technical ideas proposed in accordance with the present invention, any changes made on the basis of technical solutions, all fall within the protection scope of the present invention. Inside.

Claims (3)

1. A backup self-switching device with a regional self-switching function, which is used in a power supply system with a dual power supply series supply structure, and the dual power supply series supply structure includes two power supply stations and at least two series supply substations; it is characterized in that: the standby The self-injection device includes a regional standby automatic input device and several acquisition and execution units. The regional standby automatic input device is configured in any power station or series power substation, and several acquisition and execution units are respectively arranged in two power stations and each series power supply substation. substation, and all the acquisition and execution units exchange real-time information with the regional standby self-injection device through the optical fiber communication network; Send it to the regional standby automatic switching device, and at the same time receive the tripping and closing command issued by the regional standby automatic switching device and execute the tripping and closing action; The acquisition and execution unit corresponding to each station is connected to the bus voltage of the station, and is converted into a bus voltage sign and a bus no-voltage sign switching signal according to the set bus voltage and bus no-voltage values; According to the set incoming line fault current setting and incoming line no-current setting value, the current entering the two strings is converted into the incoming line fault current flag and the incoming line no-current flag switching signal, combined with the bus voltage, Calculate the angle between the voltage and current to obtain the direction mark of the current; collect the trip position contacts of the two series power switches for the discrimination of the system operation mode; collect the closed position contacts of the two series power switches for manual jumping of the working power supply Blocking standby self-switching; collect the action signal of bus differential protection to identify bus faults; the collection and execution unit sends the above-mentioned flags and switches to the regional backup automatic switching device through the optical fiber communication network, and the regional backup automatic switching investment device for comprehensive decision-making. 2. A backup self-switching device with regional self-switching function according to claim 1, characterized in that: said power station adopts substation, busbar or tie-line power supply. 3. A kind of method for automatic switching based on the automatic switching device with regional automatic switching function as claimed in claim 1, it is characterized in that comprising the steps: (1) Regional standby self-switching adopts charging and discharging logic. When the system is running normally, a certain string supply switch is used as an open loop point, and the rest of the string supply switches are closed for operation, and the bus voltage of each substation is under pressure. After charging and setting time, the regional backup automatic After the charging is completed, set the charging sign; (2) After the regional backup self-switching charging is completed, if there is a fault in the system or the power station loses voltage, the regional backup automatic switching device will select a series supply switch suitable for isolating the fault according to the fault situation; (3) After the trip delay, issue a command to trip the previously selected series supply switch, and the trip command is sent to the acquisition and execution unit of the corresponding substation through the optical fiber communication network to perform the trip action. Issue the closing and opening loop point series supply switch command, and the closing command is sent to the acquisition and execution unit of the substation where the open loop point is located through the optical fiber communication network to implement the actual closing.