JPH03237370A - Fault detecting method for changeover switch for shinkansen super express railway - Google Patents

Abstract

PURPOSE:To enable a detection of short-circuit caused from the fault of changeover switch by detecting a current flowing in the changeover switch at the joining position of different power sources. CONSTITUTION:The currents on the changeover switchs 4, 5 installed in changeover section 3 are detected by current transformers (CT) 11, 12. The fault is concluded when current flows in the CTs 11, 12 at the same time, because the switches 4, 5 are never thrown at the same time. At this time, the current have the same direction with same value when no train 6 exists in the section, and the different direction with different value when the train 6 exists in the section. Therefore, overcurrent elements 14, 15 are provided respectively for the CTs 11, 12 in a fault detecting device 13 and operated when the current larger than set value is mad to flow. These two outputs are inputted to an AND circuit 16, and a protective output is sent out by the device 13 when the elements 14, 15 are operated at the same time. The fault of changeover switch can be thereby detected independent of the directions of currents.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for detecting failure of a switching switch in a switching section of a Shinkansen railway where different power sources are brought together.

(Conventional technology) On Shinkansen railways, power is supplied to electric cars using single-phase alternating current, and substations are placed at intervals of 40 to 60 hours.
Matching of different power sources occurs.

Parallel connections are generally not implemented at locations where different power sources are matched, because the voltages are of different phases and the current of the electric power company flows.

On the other hand, since Shinkansen trains operate at high speeds, it is necessary to run under power even at points where different power supplies meet, so a section of about 1000 m is set up on the tram track, and power is supplied to Cefshiran using a switching switch as the train runs. There is.

When a switching switch fails, a cross current flows between different power sources based on the voltage difference and phase difference, and the current direction is from the power source to the load side at one substation, and from the load to the power source side at the other substation.

Therefore, it was possible to detect power in the opposite direction and detect a failure in the switching switch using the power direction relay installed in the substation.

However, in order to operate trains at high speeds, it is planned to introduce AC regenerative vehicles that use regenerative braking when stopping, and when AC regenerative braking is used, the power direction will be directed from the load to the power source, making it impossible to use power directional relays. Therefore, it became necessary to develop a protection method based on a new principle (Case B that the invention aims to solve) In Figure 1, at the point where different power supplies of power supply 1 and power supply 2 are brought together, the phase difference between the two power supplies generally differs. Therefore, they cannot be connected in parallel. On the other hand, Shinkansen trains run at high speeds,
Since the train runs while being supplied with electric power, a section 3 is provided and a switching switch 4.5 is used to supply electric power from the power source 1 or the power source 2 in accordance with the running of the train 6. For example, in Figure 1, when the train 6 travels from left to right, the switch 4 is on, and the switch 5 is off, and when the train 6 enters section 3, the switch 4 is off, and after about 300 m5. The switching switch 5 becomes a person. Further, when the train 6 passes through the section 3, the switching switch 5 is turned off, and then, after about 300w5, the switching switch 4 is turned on and the train returns to its original state. However, the power source 1 and the power source 2 may be short-circuited due to a failure in the operating mechanism of the switching switch or a short-circuit in the switching electrode section. That is,
If the changeover switch 5 is turned on when the train 6 enters the section 3 and the changeover switch 4 is not opened due to a failure, or when the train 6 exits the section 3 and the changeover switch 5 is not opened due to a failure. When switch 4 is turned on,
Power supply 1 and power supply 2 become short-circuited.

FIG. 2 shows a phenomenon in which the switching switch 4 or the switching switch 5 is out of order, the power supplies 1 and 2 are short-circuited, and there is no train load current. If the resistance 7 of the line connected to the power supply 1 is R+, and the reactance 8 is Xl, the impedance Z is Z, = R,
+jX. Ti.

Assuming that the resistance 9 of the line related to the source 2 is Rz and the reactance 10 is Xl, the impedance Zz is Zz = Rz +
It becomes j Xz. From this, when electric ex and power supply 2 are short-circuited, if ω is the angular frequency, then the following formula (% formula %) In other words, the short-circuit current (cross current) whose magnitude is influenced by the phase difference (θ2 - θ1) between the two power supplies is the same. It can be seen that the flow is in the same direction.

Figure 3 shows the impedance of zero train load 6, which is a phenomenon when the switching switch 4 or switching switch 5 has failed and there is a train load 6 in section 3.ZL=RL+jXL,V
+ -V2 = V, the current 11 supplied from the power supply 1 is, ■ Similarly, the current 12 supplied from the power supply a2 is (Z,
5in(ω1-θz)-2ZL sin.

Since the load current supplied from both power supplies to the train load 6 is superimposed on the short circuit current (cross current) i of the power supplies 1 and 2,
If there is no phase difference (θ2-01) between the two power supplies, the second term of the numerator will be 0,
iI and i2 are the phase difference (θ2−θ
l), the sign of the second term of the numerator is different, so the size is also different.

The present invention provides a switching switch 4 or a switching switch 5 as described above.
This is to detect a short-circuit failure between power supplies 1 and 2 due to a failure, and its purpose is to protect the power supply system to the Shinkansen railway from abnormal phenomena.

(Means for Solving the Problems) A fault detection method for a switching switch for Shinkansen railways according to the present invention is shown in FIG. The current flowing through the switch 5 is detected, and when the current flows only in one direction, it is determined to be normal, and when the current flows simultaneously, it is determined to be a short circuit due to a failure of the switching switch.

(Example) In FIG. 4, CTII is used to detect the current of the switching switch 4, and CT1 is used to detect the current of the switching switch 5.
2 is used.

The switching switch 4 and the switching switch 5 are not turned on at the same time, and a power outage of 300 IllS is involved, so it is only necessary to judge that there is a failure when current flows to CTII and CT12 at the same time. However, the current direction is as explained above. Thus, when there is no train in section 3, the values are the same in the same direction, and when there is a train, the values are different in different directions, so it is necessary to detect failures for these phenomena.

Therefore, the failure detection device 13 is provided with an overcurrent element 14 for the CTII and an overcurrent element 15 for the CT12, so that each element operates when a current exceeding a set value flows.

These two outputs are input to an AND circuit 16, and the failure detection device 13 outputs a protection output when the overcurrent element 14 and the overcurrent element 15 operate simultaneously.

Thereby, in the case of a switching switch failure, the failure can be detected regardless of the current direction.

(Effects of the Invention) As is clear from the above explanation, the method for detecting failure of a switching switch for Shinkansen railways of the present invention detects a short circuit of different power sources due to a failure of a switching switch, and Fault current (cross current) can be removed by opening. Furthermore, protection interlocking makes it possible to disconnect a faulty switching switch from the circuit and operate a backup device, which greatly contributes to the stable transportation of Shinkansen trains.

[Brief explanation of drawings]

Figure 1 is a circuit diagram of the point where different power supplies are matched in the Shinkansen railway power feeding circuit, Figure 2 is a circuit diagram when a short circuit occurs between different power supplies in the absence of train load current, and Figure 3 is a circuit diagram of the train load at the switching section. FIG. 4 is a circuit diagram when a short circuit occurs between different power sources in a certain state, and FIG. 4 is a principle diagram of the switching switch failure detection method according to the present invention. 1...Power supply 1.2--Electric a, 2.3--Switching section 4-Switching switch, 5-...Switching switch,
6...Vehicle 7...Line resistance, 8-...Line reactance 9...Line resistance, 1()--Line reactance 11--Current transformer (CT 11) 12-- ...Current transformer (CT 12) 13--fault detection device, 14--overcurrent element 15--overcurrent element,
16・-AND circuit Figure 1

Claims (1)

[Claims] At points where different power sources meet, a switching section is installed so that the train can pass under power, and the power source is switched by a switching switch as the train runs.In Shinkansen railways, the switching switch is installed using a current transformer (CT). A failure detection method for a switching switch for Shinkansen railways, characterized in that when a cross current is detected at the time of a failure, it is determined that a short circuit occurs between the poles of the switching switch.