The relay protection circuit of eliminating transformer dead band fault
Technical field
The utility model relates to a kind of relay protection circuit, relates in particular to the relay protection circuit of a kind of eliminating transformer dead band fault.
Background technology
According to " DL400-91 relaying protection and automatic safety device technical regulation " requirement; to transformer except that the necessary gas and differential protection of installing; to the transformer overcurrent that causes by outside phase fault; should install the overcurrent protection of voltage blocking in accordance with regulations protects in support; after the protection action, the band time limit moves in tripping operation.
Because the main transformer impedance is bigger, when main transformer low-pressure side fault, high side voltage often descends less, cause effectively to open the voltage blocking function, for this reason in actual applications, adopt open method in parallel, energy action message when guaranteeing the low-pressure side fault, promptly adopt the voltage of high and low pressure side simultaneously, any one voltage descends can both open locked loop.Its protection philosophy such as Fig. 2, shown in Figure 3.
According to the regulation of operation, main transformer is gone into operation or is overhauled when using as a servant again, for preventing the main transformer fault, must throw and go up main transformer differential protection and the protection fully of high and low pressure rear flank.The differential protection scope is two all devices between the current transformer, if any the instantaneous tripping main transformer of fault high and low pressure side switch.The high and low pressure rear flank is equipped with the protection of protection for the reserve of differential protection and busbar fault, the corresponding switch of action back time-delay tripping.
The actual motion operating process is the high side switch impact main transformer that at first closes; low-side switch is drawn back; if break down between the low-side switch summation current transformer this moment; because this fault is positioned at outside the differential protection scope; therefore differential protection can't move; and the voltage that the high-pressure side backup protection is got can't move opening because the main transformer impedance is big; low-pressure side bus is because voltage normally can not be by the open high-pressure side overcurrent protection in startup in parallel loop simultaneously; cause it can not excise fault fast, will cause that main transformer burns damage.Caused the protection dead band thus.
Summary of the invention
The utility model mainly be to transformer under the situation that middle pressure or low-side switch are drawn back; in fault can't protected situation between pressure or low-side switch and the respective electrical current transformer, designed two kinds of relay protection circuits of eliminating above-described protection dead bands.
Above-mentioned technical problem of the present utility model is implemented by the following technical programs:
The relay protection circuit of eliminating transformer dead band fault, on main transformer, be provided with the main transformer differential protection, also be provided with the main transformer backup protection between main transformer and each bus, select one and select following the connection: the non-high-pressure side of (1) main transformer protection switch separating brake position terminals links to each other with protection switch amount position, main transformer high-pressure side leading-in terminal; (2) protection tripping operation terminal in the non-high-pressure side of main transformer links to each other with main transformer high-pressure side protection tripping operation terminal.
As preferably, in two coil transformers, main transformer low-side switch separating brake position terminals links to each other with protection switch amount position, main transformer high-pressure side leading-in terminal.
As preferably, in two coil transformers, main transformer low-pressure side protection tripping operation terminal links to each other with main transformer high-pressure side protection tripping operation terminal.
In two coil transformers; first kind of circuit embodiment: in two coil transformers; the low-side switch position is introduced in the backup protection of high-pressure side; as accompanying drawing 3,4; by changing high-pressure side protection internal actions logic; tripping high and low pressure side switch under the prerequisite that the high-pressure side protective current disconnects greater than setting value and low-side switch is eliminated the dead band fault.
In two coil transformers; second kind of circuit embodiment: in two coil transformers; increase low-pressure side protection action and jump the wiring of high side switch; as accompanying drawing 5,6; change low-pressure side protection action logic-when low-side switch disconnect and the low-pressure side protective current greater than the prerequisite of setting value under the tripping high side switch, eliminate the dead band fault.
As preferably, in three coil transformers, in the main transformer, low-pressure side protection separating brake terminal and main transformer high-pressure side protection tripping operation terminal link to each other.
As preferably, in three coil transformers, main transformer medium voltage side protection tripping operation terminal links to each other with main transformer high and low pressure side protection tripping operation terminal.
As preferably, in three coil transformers, main transformer low-pressure side protection tripping operation terminal links to each other with main transformer height, medium voltage side protection tripping operation terminal.
In three coil transformers; first kind of circuit embodiment: the implementation of three coil transformers and two coil transformers are similar; on the basis of two coil transformers, only need increase the medium voltage side position of the switch is introduced in the backup protection of high-pressure side; change high-pressure side protection internal actions logic; the high-pressure side protective current greater than the prerequisite of setting value and any disconnection of mesolow side switch under the high, medium and low three side switches of tripping, eliminate the dead band fault.
In three coil transformers, second kind of circuit embodiment: the implementation of three coil transformers, increase the medium voltage side protection and jump the wiring of high side switch and low-pressure side, change medium voltage side protection action logic-when the medium voltage side switch disconnect and the low-pressure side protective current greater than the prerequisite of setting value under tripping high-pressure side and low-side switch, eliminate the dead band fault; Increase the low-pressure side protection and jump the wiring of high side switch and medium voltage side, change low-pressure side protection action logic-when low-side switch disconnect and the low-pressure side protective current greater than the prerequisite of setting value under tripping high-pressure side and medium voltage side switch, eliminate the dead band fault.
In sum, the utility model is compared with prior art and is had following advantage:
When low-side switch disconnection, high side switch impact main transformer, the charging equipment between the low-voltage circuit breaker summation current transformer is also being protected within the protection range situation of thoroughly having avoided main transformer to damage because of overcurrent.
Description of drawings
Fig. 1 is main transformer low-side switch operation circuit figure;
Fig. 2 be main transformer low-side switch operation circuit figure respectively distinguish functional block diagram;
Fig. 3 be main transformer low-pressure side backup protection position of the switch lead-out terminal and main transformer high-pressure side backup protection switching value input terminal annexation figure respectively distinguish functional block diagram;
Fig. 4 is main transformer low-pressure side backup protection position of the switch lead-out terminal and main transformer high-pressure side backup protection switching value input terminal annexation figure;
Fig. 5 is two coil transformer main transformer high-pressure sides protection tripping operation terminal and main transformer low-pressure side protection tripping operation terminal annexation figure;
To be two coil transformer main transformer high-pressure sides protection tripping operation terminal respectively distinguish functional block diagram with terminal annexation figure is tripped in the protection of main transformer low-pressure side to Fig. 6.
Embodiment
Below by embodiment, in conjunction with the accompanying drawings, the technical solution of the utility model is described in further detail:
Embodiment 1:
The improvement that the utility model is made with reference to national transformer standard protective device design drawing, standard is JB/T5054-2001 and JB/T8823-1998.
The utility model is not done any change to the related hardware of main transformer protection and operation circuit, and its existing equipment need not change, and the part of modification is mainly the internal processes logic and increases the portion of external secondary connection.
Fig. 2 be Fig. 1 main transformer low-side switch operation circuit figure correspondence respectively distinguish functional block diagram.Among Fig. 2 each functional areas comprised operating power from top to bottom, jumped a position supervision, combined floodgate maintenance, reclosing, anti-jump, hand closes, hand is jumped, protection is tripped, tripping operation keeps, close a supervision, closing pressure, tripping operation pressure, air pressure deficiency.
Fig. 3 is Fig. 4 main transformer low-pressure side backup protection position of the switch lead-out terminal and the corresponding functional block diagram of respectively distinguishing of main transformer high-pressure side backup protection switching value input terminal annexation figure.The main transformer low-pressure side backup protection position of the switch lead-out terminal on Fig. 3 top is respectively distinguished in the functional block diagram each functional areas and has been comprised remote signalling, the protection of main transformer reserve blind area from top to bottom, gone protection; wherein remote signalling has comprised that low-side switch separating brake position, low-side switch closing position, accident resultant signal, control loop broken string, tripping operation pressure anomaly, closing pressure are unusual; wherein main transformer reserve blind area protection has comprised low-side switch separating brake position, low-side switch closing position, wherein go protection to comprise to jump position, KK to close after.
Main transformer low-side switch operation circuit is not done any change, as shown in Figure 1, and when low-side switch punishment gate position, its position of the switch relay TWJ1, TWJ2, TWJ3 excitation, show that switch separates, as shown in Figure 4, separating brake position relay tip 622,624 closures.As shown in Figure 4; separating brake position relay tip one side 624 is received by inner optocoupler 24V power supply in the switching value importation of main transformer high-pressure side protection; when it is closed, current potential is fed back to the switching value input contact of protecting the high-pressure side by 622; this contact 309 is defined as low-side switch separating brake position by internal processes; change internal logic simultaneously, make it satisfy the effect of protection blind area fault.
The wiring of logic increase for a change; as shown in Figure 4; main transformer low-pressure side backup protection position of the switch lead-out terminal 42D35 is connected with main transformer high-pressure side backup protection switching value input terminal 309, and main transformer low-pressure side backup protection position of the switch lead-out terminal 42D36 is connected with main transformer high-pressure side backup protection switching value input terminal 317.
In two coil transformers, original internal logic is: high side voltage less than setting or low-pressure side voltage less than setting and high voltage side current the time greater than setting, time-delay high jump, low pressure both sides switch; During less than setting, low-side switch is jumped in time-delay to the low-pressure side electric current greater than setting and low-pressure side voltage.
In the main transformer backup protection of two coil transformer high voltage bus sides, more than change and make internal logic increase: when low-side switch disconnects, and high voltage side current is during greater than setting, high jump in required time, low pressure both sides switch.
Embodiment 2:
In two coil transformers, original protection logical process is: high side voltage less than setting or low-pressure side voltage less than setting and high voltage side current the time greater than setting, time-delay high jump, low pressure both sides switch; During less than setting, low-side switch is jumped in time-delay to the low-pressure side electric current greater than setting and low-pressure side voltage.
Change the part wiring; as Fig. 5, Fig. 6; main transformer low-pressure side protection tripping operation terminal 21D18 links to each other with main transformer high-pressure side protection tripping operation terminal 31D39, main transformer low-pressure side protection tripping operation terminal 21D33 links to each other with main transformer high-pressure side protection tripping operation terminal 31D67, and all the other as shown in Figure 1 and Figure 2.
In the main transformer backup protection of two coil transformer high voltage bus sides, more than change and make the internal logic process increase: when low-side switch disconnects, and the low-pressure side electric current is jumped high side switch during greater than setting in required time.
Specific embodiment described herein only is that the utility model spirit is illustrated.The utility model person of ordinary skill in the field can make various modifications or replenishes or adopt similar mode to substitute described specific embodiment, but can't depart from spirit of the present utility model or surmount the defined scope of appended claims.