JPH059941Y2 - - Google Patents

Description

[Detailed description of the invention] A. Industrial field of application This invention relates to a substation control device for electric railways.

B. Overview of the invention This invention uses an inverter-converter and a converter-inverter switchable thyristor converter in electric railway substation control equipment to detect regenerative current when the converter is switched from the converter to the inverter, and when the inverter is switched from the inverter to the converter. By absorbing the regenerative current with a dummy resistor, it is possible to prevent a voltage rise at the pangraph point of an electric car and to prevent power outages due to switching delays.

C. Prior Art Figure 3 is a schematic configuration diagram of a substation. In Figure 3, AC is an alternating current power supply, REC is a thyristor rectifier capable of switching between inverters and converters, DA ₁ and DA ₂ are first and second diodes, CB ₁ and CB ₂ are the first and second
In a static circuit breaker, this first and second static circuit breaker
CB ₁ and CB ₂ are turned on when the thyristor rectifier REC is in inverter operation. LN is a train line,
RA is a rail. A substation configured in this manner is normally controlled to have voltage characteristics as shown in FIG. In Figure 4, from point a to b
The constant voltage control characteristic range is from point A to point m, and the range from point b to c shown in the figure is a voltage fluctuation range according to the voltage fluctuation rate of the thyristor converter REC, and from point a to m shown in the figure.
The point is the voltage control region. Note that the illustrated point d is the switching setting voltage value.

Next, the operation of the substation shown in FIG. 3 will be described based on the voltage characteristics shown in FIG. 4.

(b) To switch the thyristor converter REC from converter operation to inverter operation, proceed as follows.

The first and second static circuit breakers CB ₁ and CB ₂ are off,
When the thyristor converter REC is operating in the converter mode, when the regenerative current on the electric vehicle side begins to flow, the power running current decreases and eventually becomes zero. After this, the regenerative current of the electric car is not absorbed, so the voltage at the pantograph point of the electric car increases. This voltage increase results in an increase in the substation bus voltage. Therefore, when regeneration is started and it is detected that the substation bus voltage has exceeded the set voltage value d point shown in Figure 4, the thyristor converter
Switch REC to inverter mode. Along with this switching, the first and second static circuit breakers CB ₁ ,
Turn on CB ₂ and start inverter operation.

(b) To switch the thyristor converter REC from inverter operation to converter operation, proceed as follows.

As the regeneration approaches the end, the substation bus voltage begins to drop, and at the point when it falls below the set voltage value d point shown in FIG. 4, the first and second static circuit breakers CB ₁ ,
Turn off CB ₂ and switch the thyristor converter REC to converter mode.

D. Problems to be solved by the invention (a) When switching the thyristor converter from converter operation to inverter operation as described above, if a regenerative vehicle is running, there is no load to absorb the regenerative current. As shown, the voltage at the pantograph point suddenly increases. Generally, electric cars are equipped with an overvoltage protection relay (OVR), so if the pantograph voltage rises to this protection range, the relay will operate. Then, the electric car stops regenerative braking and switches to air braking, which causes problems such as not being able to brake smoothly and causing discomfort to passengers, but also loss of regenerative power, making driving uneconomical. I become confused.

(b) Also, when switching from inverter operation to converter operation, if the regenerative current changes rapidly from the regenerative current to the powering current due to a combination of a regenerative vehicle and a powering vehicle, etc., the converter mode may not be reached due to the switching delay. arise. In such a case, if the electric vehicle has an auxiliary device using a thyristor or the like, there is a problem that the auxiliary device will stop even in a 5ms power outage.

E. Means for Solving Problems This invention is a stationary substation equipped with a thyristor converter that can switch between inverters and converters, a static circuit breaker that is turned on during inverter operation, and a diode that conducts power running current. A series circuit of a type circuit breaker and a dummy resistor is provided, and the opening/closing of the static type circuit breaker provided in the series circuit is controlled by the output of a current detector provided in the energized path.

F Effect When the current flowing through the current path decreases from the positive side to zero according to the current detector, the thyristor converter is switched from converter mode to inverter mode, the static breaker is turned on, and the regenerative current is absorbed by the dummy resistor. do. After that, when the current decreases from zero to a set value on the negative side, the static circuit breaker is turned off to stop absorbing the regenerative current.

Further, when the current decreases from the negative side and reaches a set value on the negative side, the thyristor converter is switched from the inverter mode to the converter mode, and the regenerative current is absorbed by the dummy resistor. After that, when the current becomes positive, the static circuit breaker is turned off to stop absorption using the dummy resistor.

G. Embodiment An embodiment of this invention will be described below with reference to the drawings. The same parts as in FIGS. 3 and 4 will be described with the same reference numerals.

In FIG. 1, a series circuit of a third static circuit breaker CB ₃ of the illustrated polarity and a dummy resistor RD is connected between the cathode side of the first diode DA ₁ and the anode side of the second diode DA ₂ . DCT is a direct current transformer that detects the substation current, and depending on the state of the current detected by this current transformer DCT, the thyristor converter REC
converter mode, inverter mode switching,
Performs on/off control of each static circuit breaker CB ₁ to CB ₂ .

Next, the operation of the embodiment configured as described above will be described with reference to FIG.

(a) To switch the thyristor converter REC from converter operation to inverter operation, proceed as follows.

The DC current transformer DCT detects that the substation current decreases from the positive side and reaches zero, and provides the detection to a control unit (not shown). The control unit gives an ON command to the first to third static circuit breakers CB ₁ to CB ₂ and also gives a command to switch the thyristor converter REC from converter mode to inverter mode. This point is point _e1 shown in FIG. When the third static circuit breaker CB ₃ is turned on and the converter mode is switched to the inverter mode, the regenerative current flows through the third static circuit breaker CB ₃ to the dummy resistor RD and is consumed there. As a result, a voltage increase in the pantograph of an electric car will not occur. The switching time from converter mode to inverter mode is approximately
It is 20ms. After that, when the DC current transformer DCT detects that the current has decreased from zero to the negative set value (point f ₁ in Figure 2), the controller gives an OFF command to the third static circuit breaker CB ₃ . .

(b) Next, to switch the thyristor converter REC from inverter operation to converter operation, proceed as follows.

The substation current decreases from the negative side to the set value on the negative side
Since the f ₂ point has been reached, an OFF command is given to the first and second static circuit breakers CB _{1 and} CB ₂ , an ON command is given to the third static circuit breaker CB ₃ , and the thyristor converter REC is switched to the inverter. Gives a command to switch from mode to converter mode. At the time of this switching, the regenerative current decreases, but because the third static circuit breaker is closed before regeneration ends, the regenerative current flows through the dummy resistor RD and is consumed. Thereby, a delay in the output of the power running current at the time of switching from inverter operation to converter operation can be prevented.
Note that the positive current has started to flow (as shown in Figure 2).
When the DC current transformer DCT detects (point e ₂ ), an off command is given to the third static circuit breaker CB ₃ .

Here, as an example, a specific example of the case of a Chiyotsupa vehicle will be described.

The current increase rate at the start of regeneration in the Chiyotsupa vehicle is 644A/S. Therefore, the current that flows when the switching time is 20ms is 644A/S x 20 x 10 ^-3 (S) =
12.88(A).

In addition, the regeneration end value is 276A/S on Chiyotsupa vehicle.
When the switching time is 20ms, it is 276A/S x 20
×10 ^-3 =5.52 (A) Therefore, if the negative setting value set in the control device of the above embodiment is -20A, sufficient switching can be performed in 20ms.

Note that the loss when the regenerative current is passed through the dummy resistor is calculated as follows. Assume that switching occurs four times in one minute.

20ms x 60 minutes x 1500V x 20A x 2/3600 = 0.02KW In the above example, the second and third static circuit breakers CB ₂ ,
Although the CB ₃ has been described as a circuit breaker, it can also be a static switch.

H. Effects of the invention As described above, according to this invention, the regenerative current during the switching time when switching the thyristor converter from the converter to the inverter is consumed by the dummy resistor, so the voltage rise at the pantograph point does not occur. do not have. Furthermore, when switching the thyristor converter from an inverter to a converter, the switching is done while absorbing regenerative current with a dummy resistor, so there is no switching delay and no power outage occurs.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration explanatory diagram showing one embodiment of this invention, Fig. 2 is a voltage characteristic diagram of the substation shown in Fig. 1, Fig. 3 is a schematic configuration diagram of a conventional substation, and Fig. 4 is a diagram showing the voltage characteristics of the substation shown in Fig. 1. 4 is a voltage characteristic diagram of the substation in FIG. 3. FIG. REC……thyristor converter, CB ₁ , CB ₂ , CB ₃
...First to third static circuit breakers, DA ₁ , DA ₂ ...
1st and 2nd diodes, RD...dummy resistor,
DCT...DC current transformer.

Claims (1)

[Claims for Utility Model Registration] A thyristor converter that can be switched from an inverter to a converter and from a converter to an inverter, a first diode inserted in an electric path between the positive output end of this converter and a feeder line, and a converter. a second diode inserted between the negative output terminal of the first diode and the ground;
a first static circuit breaker whose anode side is connected to the cathode side of the diode and whose cathode side is connected to the cathode side of the second diode;
In a substation of an electric railway including a second static type circuit breaker whose cathode side is connected to the anode side of the diode, a third static type circuit breaker connected between the cathode side of the first diode and the anode side of the second diode. A series circuit of a circuit breaker and a dummy resistor, a current detector provided in a current supply path to the feeder line, and a control unit to which an output detected by the current detector is provided, the control unit , when the detector detects that the substation current decreases from the positive side and becomes zero, an on command is given to the first to third static circuit breakers and the thyristor converter is switched from the converter mode. A command is given to switch to the inverter mode, and when the detector detects that the current has decreased from zero to a first set value on the negative side, a command is given to the third static circuit breaker to turn off, and the current is When the detector detects that the value has decreased from the negative side and reached the second set value on the negative side, it issues an OFF command to the first and second static circuit breakers and an ON command to the third static circuit breaker. and gives a command to switch the thyristor converter from inverter mode to converter mode, and gives an off command to the third static circuit breaker when the detector detects that the positive current has started flowing. A substation control device for an electric railway, characterized in that it sends out control commands.