JPH03132436A - Different power supply mixed-contact detecting system and device therefor - Google Patents

Abstract

PURPOSE:To enable the positive detection of a mixed-contact accident in a device with dissimilar power sources connected through respectively separate breakers by detecting a current flowing simultaneously to each breaker so as to detect the mixed contact of the dissimilar power sources. CONSTITUTION:At the time of a vehicle 8 travelling to the left, a breaker 6 is charged right before the vehicle 8 reaching an insulating means 4 make the voltage of a switching section 3 the same as that of a feeder AT, and after the approach of the vehicle 8, the breaker 6 is cut off before the vehicle 8 reaching an insulating means 5 as well as a breaker 7 is charged so that the vehicle 8 is brought into contact with a B-seat generating line BT and passes between dissimilar power sources, in the non- arc state. In case a phase mixed-contact accident is generated at this time, a current flows in the direction f an arrow mark, and exactly the same current flows to current detecting devices 10, 11. Detecting means 121, 123 are therefore energized respectively at the same time to close their normally-opened contacts 121a, 123a, as well as a detecting means 122 is reset to close its normally opened contact 122b. Signals are thereby outputted from output terminals 13, 14 to perform warning or other necessary protecting action.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a technology for detecting the mixing of different types of power sources, such as power source matching between power supply sections of electric railways or substations.

B0 Summary of the Invention The present invention is designed to reduce the current flowing through the circuit breaker, which cannot be distinguished from general ground faults or short circuits when a different phase contact accident or different phase contact accident occurs in a switching breaker for different power sources. This system is designed to reliably detect cross-contact accidents between different types of power supplies and distinguish them from general accidents.

C1 Conventional technology In power supply systems such as the Shinkansen and the Tsugaru Kaikyo Line, a large number of different types of power sources are connected via switching circuit breakers. Since the electric railway load is a single-phase load, three-phase to single-phase conversion is generally performed using a Scott transformer or a modified Woodbridge transformer.

Figure 2 is a wiring diagram showing an example of a modified Woodbridge connection, in which 1 shows a three-phase to two-phase conversion transformer, 2 shows a step-up transformer, and the three-phase to two-phase conversion transformer 1 is a primary The windings are Y-connected,
Connected to power. The secondary winding has a double triangular connection in which V-phases are connected in parallel.

The voltage between one set of output terminals a and c of this secondary winding is transferred to the bus lines T and F of A, and the output terminal of the step-up transformer 2 connected to the other set of output terminals b'd'. .

The voltage between 6 and 6 is connected to the bus lines T' and F' of the B seat.

If the voltage of the output terminals a and cfJT is V, the voltage between the other set of output terminals b' and d' is v2/(,
The phase difference between the voltages between terminals a and c and between terminals b' and d' is 90 degrees.

The step-up transformer 2 boosts the voltage v, /( between the terminals b' and d', and generates the voltage ■, between the output terminals S and 6. 3 is a switching section, and the voltage V, /( between the terminals b' and d' is increased. It is located between the connected feeder line AT and the feeder line BT connected to the bus line T of the B seat, and is insulated from the feeder line by insulation means 4 and 5. to the A seat bus line T via the circuit breaker 7, and to the 13 seat bus line 1 via the breaker 7.
Connected to ゛′. 8 indicates a vehicle such as a train.

Note that a vacuum breaker is used as the circuit breaker 6.7.

The operation of the switching breaker is as follows: If the vehicle 8 is moving from the right side to the left side in the figure, the breaker 6 should be turned on before the vehicle 8 reaches the insulating means 4. At this time, the breaker 7 is in the cut off state.
, the switching safety controller 3 is set to the same voltage as the feeder line AT and then entered, and after entering, the breaker 6 is cut off before reaching the insulating means 5, and at the same time, the breaker 7 is turned on and connected to the B seat bus BT, and a different power source is connected. Pass through the space without arcing.

D1 Problem to be Solved by the Invention The switching circuit breakers 6 and 7 described above are always in the closed state, and are switched in accordance with the progress of the train, so the number of operations reaches tens of thousands of times a year. Failure detection and life management of switching circuit breakers are required.

In addition, if a breaker is in a energized state due to arcing, etc., and another breaker is turned on while the current is not completely cut off, causing contact between different types of power supplies, a different phase contact accident or a different phase contact accident will occur, and the feeder line or bus bar Alternatively, current flows through the transformer windings in a complicated path, causing a breaker such as a power supply to be disconnected. This fault current is indistinguishable from general ground faults and short circuit faults, and therefore,
Thinking that it was a temporary ground fault (short circuit) in the bare external wire, the operator repeatedly forced the circuit breaker to turn on again, causing severe damage to the switching breaker, which could even lead to a fire, and it would take a lot of time to recover from the accident. There are problems such as the need for personnel.

Further, it is difficult to detect different phase contact and different frequency contact by comparing phases and frequencies, and there has been no appropriate means for detecting mixed contact accidents.

Therefore, an object of the present invention is to provide a method that can distinguish these accidents caused by contact between different types of power sources from general accidents, and can also reliably detect them.

E1 Means for solving the problem The means for solving the above problem focuses on the fact that the same current flows through both switching circuit breakers when different types of power sources come into contact, and detects the current flowing through each of the circuit breakers, When current flows through both circuit breakers at the same time, it is determined that there is a cross-contact between different types of power sources.

Further, a contact detection relay is provided which detects the current flowing through both switching circuit breakers and outputs an output when the current flows through both circuit breakers at the same time, but does not output when the current flows through only one of the circuit breakers.

F0 action During normal operation, only one of the two switching circuit breakers is always in the on state, and when a cross-contact occurs between different types of power sources, current flows in the direction shown by the arrow in Figure 1, and both circuit breakers are completely disconnected. Since the same current flows, it is determined that there is a cross-contact accident by detecting the current flowing through both circuit breakers at the same time, and if only one is flowing, it is determined to be normal.

G. Example Hereinafter, the present invention will be explained based on an example shown in FIG. Note that the same reference numerals as in FIG. 2 are given to the same or the same functional parts as in FIG. 2, and the explanation thereof will be omitted.

IO and II are current detection devices for detecting the currents flowing through the circuit breakers 6 and 7, respectively, and are comprised of, for example, current transformers. Reference numeral 12 denotes a contact detection relay, and the contact detection relay 12 is equipped with detection means 121, 122, and 123 consisting of primary and secondary coils. This detection means 1
21 and 123 are connected to the current detection devices 10 and 11, respectively, and the detection means 122 consists of two primary coils, and the polarity is reversed to connect the current detection devices 10 and 11.
or in series with the primary coils of the detection means 121 and 123. The secondary side of each of these detection means has a contact that opens and closes with a secondary induced voltage. The contacts 121 and 123 are normally open contacts 121a and 1
23a, and the detection means 122 has a normally closed contact 122b.
has.

Each of these contacts is connected in series to an output contact terminal 13.
14.

Next, to explain the operation, since only one of the circuit breakers 6 or 7 is always closed when the train is under constant load, either one of the detection means 121 or 123 and one coil of the detection means 122 are connected. energized, a voltage is generated in the secondary coil, and the normally open contact 1 of the detection means +21 or 123
One of 21a or 123a is closed and the other is open, and the detection means 122 is always active and opens the normally open contact 122b.

Therefore, no contact output is output to the output contact terminals 13 and 14.

Next, for example, when a different phase contact accident occurs, the current flows in the direction shown by the arrow, and the exact same current flows through both current detection devices 10 and 11. As a result, the detection means 12
1 and 123 are energized simultaneously, and their normally open contacts 121a,
123a is closed, and at the same time, the primary side of the detection means 122 cancels each other out and no voltage is generated on the secondary side, so it returns to its normal state and closes its normally closed contact 122b. Therefore, contact +21a, 1
22b and 123a are all closed, and a contact output is output to 14, which detects contact with the output terminal 13 by comparing phases and frequencies, thereby causing an alarm or necessary protective operation to be performed. In the case of no load, 12Ia, I23a is open, 12
2b is closed and no contact output is output.

In addition, in the above embodiment, the explanation was given regarding the mixture of different phases at a substation, but it can also be applied to a feeder distribution station where the power source is matched between substations, and it can be applied to the mixing of 50Hz, 601- It can also be applied to detection of contact between different types of power sources.

Further, the contact detection relay is not limited to a coil and a contact output, but can of course be constructed by a logic circuit using a semiconductor element.

H9 Effects of the Invention As stated in 2, the present invention focuses on and detects the current flowing through the switching breaker, rather than detecting cross-phase or different-frequency cross-contamination. Since accidents can be detected reliably and can be detected separately from general ground faults and short circuits, signs of deterioration of the switching breaker can be detected early and the service life of the switching breaker can be appropriately managed. It has excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a wiring diagram showing one embodiment of the present invention, and FIG. 2 is a wiring diagram of a conventional example. l... 3-phase 2-phase conversion transformer, 2... pressure transformer,
3 switching section, 4.5 insulation means, 6.7...
Switching breaker, 8... Vehicle, 10. II - Current detection device.

Claims (2)

[Claims] (1) In devices where different types of power sources are connected to the switching section through separate circuit breakers, the current flowing through each of the above-mentioned circuit breakers is detected, and the current flowing simultaneously through both circuit breakers is detected to prevent cross-contact between different types of power sources. A method for detecting cross-contamination of different power sources. (2) In a device in which different types of power sources are connected to the switching sections through separate circuit breakers, a detection means is provided for detecting the current flowing through each of the circuit breakers as an electrical signal, and a signal detected by both of the detection means is provided. A cross-contact detection device for different power sources, characterized in that a cross-contact detection relay is provided that outputs an output when only one of the signals is received, and does not output an output when only one of the signals is received.