A half breaker mode of connection Down Highway is protected the recognition methods of non-complete string operational mode
Technical field
The present invention relates to a half breaker mode of connection Down Highway and protect the recognition methods of non-complete string operational mode, belong to the bus protection technical field.
Background technology
A half breaker mode of connection (claiming 3/2 breaker connection mode again) is a kind of operational mode high voltage bus mode of connection very flexibly, is usually used in the above system of 330kV.3/2 breaker connection utilizes the redundancy of circuit breaker, and circuit or element are connected on two buses, and its advantage has: be convenient to linkage unit and switch between different buses; Busbar fault does not influence linkage unit and continues operation; Operation is easy etc.Fig. 1 is 3/2 breaker connection mode schematic diagram.
Also there are some shortcomings simultaneously in 3/2 breaker connection mode, as: the cost height; Improve the complexity of relaying protection.
The relative double-bus protection of the bus protection of 3/2 breaker connection mode is comparatively simple; according to the relevant operating provisions of China's electric power system; 3/2 breaker connection mode is according to the fixing bus protection of dualization of bus bar configuration; i.e. bus bar configuration two cover protections; the string top switch that this bus of bus protection action excision connects, bus protection need not the composite voltage locking simultaneously.
A major issue of the bus protection under the 3/2 breaker connection mode is: the introducing of imperfect string.With reference to figure 1, because imperfect string can switch between two buses, its current transformer is installed in a side of switch, so transformer current should count the differential circuit of different buses according to the difference of operation bus.Therefore, for protection, should calculate the spill current of protected bus according to the operational mode of unit on the imperfect string according to bus bar configuration.
The differential problem that fundamentally solves imperfect string only could solve at isolating switch side installation current transformer, and with reference to figure 2, but this method has increased the investment of primary equipment, has bus differential protection dead band between current transformer and circuit breaker simultaneously.
The operational mode identification problem of non-complete string, traditional solution is to use bus isolating switch, the method for compounding practice pressing plate, concrete grammar is:
1. this side bus isolating switch closes, offside bus isolating switch branch, and four whole correspondences of isolating switch aided location are as the criterion with isolating switch.
2. any isolating switch is not corresponding then reports to the police, and throws to move back with pressing plate to be as the criterion.
3. the position determined of pressing plate and isolating switch is not corresponding, is as the criterion and reports to the police with isolating switch.
4. two isolating switches all close, and then locking is female poor, not locking failure protection.
Its advantage is: switch current transformer secondary circuit not, and the method for using software to switch, fail safe is higher.But also have significant disadvantages: pressing plate more (2 bus is joined 4 covering devices, increases by 4 pressing plates) is unfavorable for that the operations staff operates; Pressing plate with outside open into the isolating switch auxiliary contact have overlappingly in logic, be unfavorable for determining actual operating.
Summary of the invention
Technical problem to be solved by this invention is; pressing plate at the operational mode recognition methods of existing non-complete string is more, be unfavorable for that the operations staff operates, is unfavorable for to determine deficiencies such as actual operating, provides an a kind of half breaker mode of connection Down Highway to protect the recognition methods of non-complete string operational mode.
The technical solution adopted for the present invention to solve the technical problems is as follows: a half breaker mode of connection Down Highway is protected the recognition methods of non-complete string operational mode, it is characterized in that step is as follows:
(1), detect new isolating switch auxiliary contact open into;
(2), detect the closed situation of this side, offside bus isolating switch;
(3) if this side bus isolating switch separates, and offside bus isolating switch closure, then newly differentiate the result and run on side bus for imperfect string, go to step (8), otherwise go to step (4);
(4) if this side bus isolating switch closure, and the offside bus isolating switch is separately, then newly differentiates the result and runs on this side bus for imperfect string, goes to step (8), otherwise goes to step (5);
(5) if this side bus isolating switch closure, and offside bus isolating switch closure, then locking bus differential protection and alarm finish identification, otherwise go to step (6);
(6) if this side bus isolating switch separately, and the offside bus isolating switch is separately, then keeps the differentiation result that stores in the internal memory, otherwise goes to step (7);
(7), this side bus or not corresponding to any isolating switch auxiliary contact of side bus, keep the differentiation result and the alarm of storing in the internal memory;
(8), will newly differentiate the differentiation result who stores in result and the internal memory compares; if newly differentiating the differentiation of storing in result and the internal memory comes to the same thing; then finish identification,, judge then whether circuit breaker has electric current if inequality; if circuit breaker no current; then replace the differentiation result who stores in the internal memory with new differentiation result, bus protection uses the new result of differentiation to calculate spill current, if circuit breaker has electric current; the differentiation result who stores in the maintenance internal memory, and alarm.
Beneficial effect of the present invention is as follows: the present invention combines the mode recognition logic that the current circuit broken string is differentiated, improved the automaticity in the running and the self-test capability of makeing mistakes, in normal running, the process of falling the bus of any imperfect string, need not operate the bus protection pressing plate, because the location keeps and electric current broken string logic, even any loop fault takes place, also can not cause the protection misoperation; Switch has stream to differentiate logic, has solved in the equipment running process, opens into abnormal conditions occurring.
Description of drawings
Fig. 1 is typical 3/2 circuit breaker bus mode of connection schematic diagram.
Fig. 2 is for increasing the bus mode of connection schematic diagram that CT solves imperfect string scheme.
Fig. 3 protects non-complete string operational mode recognition methods flow chart for a half breaker mode of connection of the present invention Down Highway.
Fig. 4 is the introducing schematic diagram of isolating switch auxiliary contact of the present invention.
Fig. 5 is for adopting the operation logic figure of recognition methods of the present invention.
Embodiment
With reference to the accompanying drawings and in conjunction with the embodiments the present invention is described in further detail.But the invention is not restricted to given example.
Be illustrated in figure 3 as a half breaker mode of connection of the present invention Down Highway and protect the recognition methods of non-complete string operational mode, it is characterized in that step is as follows:
(1), detect new isolating switch auxiliary contact open into;
(2), detect the closed situation of this side, offside bus isolating switch;
(3) if this side bus isolating switch separates, and offside bus isolating switch closure, then newly differentiate the result and run on side bus for imperfect string, go to step (8), otherwise go to step (4);
(4) if this side bus isolating switch closure, and the offside bus isolating switch is separately, then newly differentiates the result and runs on this side bus for imperfect string, goes to step (8), otherwise goes to step (5);
(5) if this side bus isolating switch closure, and offside bus isolating switch closure, then locking bus differential protection and alarm finish identification, otherwise go to step (6);
(6) if this side bus isolating switch separately, and the offside bus isolating switch is separately, then keeps the differentiation result that stores in the internal memory, otherwise goes to step (7);
(7), this side bus or not corresponding to any isolating switch auxiliary contact of side bus, keep the differentiation result and the alarm of storing in the internal memory;
(8), will newly differentiate the differentiation result who stores in result and the internal memory compares; if newly differentiating the differentiation of storing in result and the internal memory comes to the same thing; then finish identification,, judge then whether circuit breaker has electric current if inequality; if circuit breaker no current; then replace the differentiation result who stores in the internal memory with new differentiation result, bus protection uses the new result of differentiation to calculate spill current, if circuit breaker has electric current; the differentiation result who stores in the maintenance internal memory, and alarm.
Fig. 4 is the introducing schematic diagram of isolating switch auxiliary contact of the present invention, and Fig. 5 is for adopting the operation logic figure of recognition methods of the present invention.Among Fig. 5-L1_NO represents: the normally opened contact that connects protected bus isolating switch;-L1_NC represents: the normally-closed contact that connects protected bus isolating switch;-L2_NO represents: the normally opened contact that connects non-protection bus isolating switch;-L2_NC represents: the normally-closed contact that connects non-protection bus isolating switch.
1 pair of operational mode recognition methods of the present invention of associative list is described, and in the table 1 ,-L1_NO represents: the normally opened contact that connects protected bus isolating switch;-L1_NC represents: the normally-closed contact that connects protected bus isolating switch;-L2_NO represents: the normally opened contact that connects non-protection bus isolating switch;-L2_NC represents: the normally-closed contact that connects non-protection bus isolating switch, one of " 1 " in table expression open into high potential, " 0 " expression open into electronegative potential, this method from the auxiliary contact that detect new isolating switch open into, detect the closed situation of this side, offside bus isolating switch, judge at first whether the position of gathering is sequence number 6 states in the table 1, be that this side bus isolating switch separates, and offside bus isolating switch closure, just the isolating switch position is determined then newly to differentiate the result and run on side bus for imperfect string to side bus; If the isolating switch position is not to side bus, whether then judge the isolating switch position at this bus, i.e. table 1 sequence number 9 states, just this side bus isolating switch closure, and the offside bus isolating switch is separately newly differentiated the result and is run on this side bus for imperfect string; If this side bus isolating switch closure, and offside bus isolating switch closure, promptly collection position is sequence number 10 states in the table 1, and locking bus differential protection and alarm finish identification; If this side bus isolating switch closure, and offside bus isolating switch closure, be that collection position is sequence number 5 states in the table 1, show that two isolating switches are all in a minute position, locking bus differential protection and alarm finish identification, and this situation explanation circuit breaker is stopped transport, answer no current this moment, system will mode be fixed on the preceding running status of stopping transport; Four kinds of situations all do not meet before, illustrate that the auxiliary contact of isolating switch often leave with normally closed not corresponding, keep original position this moment, and alarm; If satisfy first, second condition; compare newly differentiating the differentiation result who stores in result and the internal memory, come to the same thing, then finish identification if newly differentiate the differentiation of storing in result and the internal memory; if it is inequality; judge then whether circuit breaker has electric current, if the circuit breaker no current is then replaced the differentiation result who stores in the internal memory with new differentiation result; bus protection uses the new result of differentiation to calculate spill current; if circuit breaker has electric current, the differentiation result who stores in the maintenance internal memory, and alarm.
The present invention judges differential current, if differential current continues 1s greater than the broken string definite value and less than starting current (being the maximum rated load electric current), promptly reports the current circuit broken string, and withdraws from differential protection.
The software processing method of table 1 isolating switch running status correspondence
In the table 1 one of " 1 " expression open into high potential, " 0 " expression open into electronegative potential.