CN202488206U - 110kV system one master and one backup self-switching bus area fault blocking device - Google Patents

Abstract

The utility model discloses a 110kV system-main-standby self-switching bus area fault blocking device, which is used to separate the incoming line interval current transformer and the outgoing line interval current transformer in the 110kV system-main-standby self-injection primary equipment. The polarity end of the secondary winding is connected in parallel, the non-polarity end is connected in parallel, and then a differential starting element relay is connected in parallel to form a differential circuit starting unit. One end of the relay's normally open contact is connected to a blocking circuit opening point of the standby self-injection , and one end is connected to the public power end of the standby self-injection. When a fault occurs in the busbar area, the fault current is sensed by the secondary winding of the current transformer between the incoming and outgoing lines, the relay is excited, the normally open contact of the relay is closed, and the voltage signal triggers the opening point of the blocking circuit of the standby automatic switching, and the standby automatic switching realizes blocking. In this way, the locking device can be used as an independent physical device, and can also be embedded in the existing backup automatic switching system, which very conveniently realizes the blocking function of the standby automatic switching system when a fault occurs in the busbar area.

Description

110kV system one master and one backup self-switching bus area fault blocking device

technical field

The utility model relates to the technical field of safe operation of electric power systems, in particular to a fault locking device for a 110kV system-master-standby self-injection bus area area.

Background technique

Standby automatic switching is the abbreviation of the device for automatically putting into use the backup power supply. The function of the backup self-switching system of the power supply is: in the case of a sudden loss of the working power supply, the backup power supply is automatically switched on, and the power consumption of the equipment that loses voltage is quickly restored to ensure the continuity of the power supply. Judging from the operation situation in the past two years, there are obvious advantages such as simple equipment and stable operation, which play a key role in improving the reliability of power supply.

As shown in Figure 1, the current 110kV system partly adopts the operation mode of one main and one backup wiring. It can be seen from the action logic of the installed standby automatic switching system that when faults occur at point d1 on the 1M bus and d2 on the 2M bus as shown in Figure 1, the standby automatic switching system cannot determine whether the grid failure is caused by a line fault or a bus fault. , no matter what the situation is, the standby automatic switch will act to automatically and blindly switch on the backup power. If the fault is caused by the equipment connected to the busbar at this time (equipment failure includes the failure of the busbar, equipment connection line, circuit breaker, knife switch, voltage transformer, current transformer and other equipment), the backup power supply will expand the fault automatically. scope.

In order to avoid the above situation, one of the blocking discharge conditions set by the standby automatic switching system is the input of blocking signals such as the bus differential protection action. Block discharge to prevent mis-casting. However, at present, the buses of some 110kV system substations are not equipped with bus differential protection, that is to say, there is no bus differential protection action to enter the standby automatic switching, so the above-mentioned mis-switching cannot be prevented, forming a major defect of blind input of standby automatic switching.

Utility model content

The purpose of this utility model is to propose a 110kV system-master-standby self-switching bus area fault blocking device, when the bus area fails, the standby self-switching can realize the locking function.

The utility model 110kV system one master one backup self-inputting bus area failure locking device includes a differential circuit starting unit, the differential circuit starting unit includes parallel relays and 110kV system one master one backup self-introducing primary equipment The current transformer for the incoming line interval and the current transformer for the outgoing line interval, the polarity ends and the nonpolar ends of the secondary windings of the incoming line interval current transformer and the outgoing line interval current transformer are connected in parallel, and the normally open One end of the contact is connected to the opening point of a blocking circuit of the 110kV system, one master and one backup, and the other end is connected to the public power terminal of the 110kV system, one master and one backup.

Preferably, it also includes a throwing and retreating pressure plate, which is connected between the normally open contact of the relay and the opening point of the locking circuit of the 110kV system, one master and one standby, and the disconnection of the throwing and retreating pressure plate corresponds to the locking device The exit mode, the throwing and retreating platen is put into the bus fault blocking mode corresponding to the blocking device.

Preferably, the number of the incoming line interval transformer and the outgoing line interval transformer are both two.

The utility model 110kV system one master one backup self-switching bus area failure locking device, the 110kV system one master one backup self-switching primary equipment of the incoming line interval current transformer and the secondary winding polarity of the outgoing line interval current transformer The ends are connected in parallel, the non-polar ends are connected in parallel, the polar and non-polar segments are connected in parallel to form a current loop, and then connected in parallel with a differential starting element relay to form a differential circuit starting unit, one normally open contact of the relay is connected to one end It is the opening point of a blocking circuit of the standby automatic switch, and one end is connected to the public power supply terminal of the standby automatic switch. When a fault occurs in the busbar area, the fault current is sensed by the secondary winding of the current transformer between the incoming and outgoing lines, the relay of the differential starting element is excited, the normally open contact of the relay of the differential starting element is closed, and the voltage signal triggers the blocking circuit of the standby self-switching to open. point, the standby auto-switching realizes locking. In this way, the locking device can be used as an independent physical device, and can also be embedded in the existing backup automatic switch, which very conveniently realizes the blocking function of the backup automatic switch when a fault occurs in the busbar area.

Description of drawings

Figure 1 is a schematic diagram of the wiring operation mode of the 110kV primary equipment with one main power supply and one backup power supply;

Fig. 2 is a structural schematic diagram of the core device differential loop start-up unit of the 110kV system of the utility model, one master and one backup self-switching bus area fault blocking device;

Fig. 3 is a schematic diagram of the structure of the utility model 110kV system, one master, one backup self-switching bus area fault blocking device and standby self-switching;

Fig. 4 is a schematic diagram of the overall structure of the 110kV system of the utility model including the switch-on and return-press plate, one master and one backup self-switching bus area fault blocking device and standby self-switching.

Detailed ways

In order to make the standby automatic switch realize blocking when a fault occurs in the bus area, it should first be able to detect the fault in the bus area. The analysis shows that when any fault point occurs on the 1M bus or 2M bus shown in Figure 1, if a fault occurs at point d1, all fault currents in the system will flow to fault point d1, and current transformers CT1, CT2, CT3, and CT4 are all A fault current is sensed. This locking device not only utilizes the characteristics that the current transformer can sense the fault current in the busbar area, but also uses the current transformer to form a differential loop starting unit as the detection element of the busbar area fault and the trigger element of the blocking signal, so as to realize the blocking of the standby automatic switching. The locking device will be explained in detail below in conjunction with the accompanying drawings.

Figure 1 is a schematic diagram of the wiring operation mode of 110kV one main and one backup power backup self-injection primary equipment. It can be seen that there are only two intervals on the same bus. For example, there are only running interval lines and #1 main transformer on the 1M bus, and there are only standby Interval line and #2 main transformer, that is to say, there are only four intervals at most in the whole station, which has the characteristics of simple wiring. Among them, the current transformers CT1 and CT3 are current transformers for the incoming line interval, and the current transformers CT2 and CT4 are the current transformers for the outgoing line interval. In the utility model, the polarity ends of the secondary windings of the incoming line interval current transformers CT1 and/or CT3 and the outgoing line interval current transformers CT2 and/or CT4 are connected in parallel, and the nonpolar ends are also connected in parallel, polarity and nonpolarity The segments are connected in parallel to form a current loop and then connected in parallel with a differential starting element relay to form a differential loop starting unit. The differential starting element relay CJ in the starting unit is the core device of the locking device.

As a preferred embodiment, as shown in FIG. 2 , the secondary windings of four current transformers CT1 , CT2 , CT3 and CT4 and the differential starting element relay CJ are connected in parallel to form a differential loop starting unit.

Take a normally open contact CJ-1 from the differential starting element relay CJ to form the logical condition of the standby automatic switching, that is, when CJ-1 is closed, the standby automatic switching is blocked. For this reason, as shown in Figure 3, one end of the normally open contact CJ-1 is connected to a blocking circuit input point N of the standby automatic switching device, and the other end is connected to the common power terminal of the standby automatic switching device, namely COM+24V. In this way, when a fault occurs in the bus area, the differential starting element relay CJ in the differential circuit starting unit is excited, and the normally open contact CJ-1 of the differential starting element relay CJ is closed. After the normally open contact CJ-1 is closed, the locking device uses The input point N of the blocking circuit of the standby automatic switching device and the common power terminal of the standby automatic switching device, that is, COM+24V, form a loop, and the voltage signal flows from the public power terminal through CJ-1 to the blocking circuit opening point N of the standby automatic switching device. , The self-injection device receives the locking signal to realize the locking function.

For the convenience of use, the locking device also includes a throwing and withdrawing pressure plate LP that is manually controlled to be turned on or off. Preferably, as shown in FIG. 4 , LP is connected between the normally open contact CJ-1 of the differential starting element relay and the input point N of the locking circuit. When the standby automatic switch needs to be locked when the bus area is faulty, the staff will put LP into it, and the blocking device works in the bus fault blocking mode; when the standby automatic switch does not need to be blocked when the bus area fails, disconnect the LP, The locking device both works in the exit mode.

The specific implementation manners of the utility model described above are not used to limit the scope of protection of the utility model, but illustrate the feasible embodiments of the utility model. Any modification, equivalent replacement and improvement based on the spirit and principles of the present utility model shall be included in the protection scope of the claims of the present utility model.

Claims (3)

1. A 110kV system one main one standby self-switching bus area fault blocking device, characterized in that it comprises a differential loop starting unit, and the differential loop starting unit comprises a parallel relay and a 110kV system one main one standby self Input the incoming line interval current transformer and outgoing line interval current transformer in the primary equipment, the secondary winding polarity end of the incoming line interval current transformer and the outgoing line interval current transformer are connected in parallel, and the non-polarity end is connected in parallel, so One end of the normally open contact of the above relay is connected to the opening point of a closed loop of the 110kV system, one master and one backup, and the other end is connected to the public power terminal of the 110kV system, one master and one backup. 2. The 110kV system-main-standby self-switching bus area fault blocking device according to claim 1, characterized in that it also includes a switch-on/return pressure plate connected to the normally open contact of the relay and the 110kV system-main-standby Between the opening points of the blocking circuit for self-switching, the switch-on/return pressure plate is disconnected corresponding to the exit mode of the blocking device, and the switch-on/return pressure plate is turned on corresponding to the bus fault blocking mode of the blocking device. 3. The 110kV system-main-standby self-switching bus area fault blocking device according to claim 1 or 2, characterized in that the number of the incoming line interval transformers and the outgoing line interval transformers are both two.

Images