JPS61200038A - Direct current feeder - Google Patents

Abstract

PURPOSE:To always maintain a proper voltage by matching the output voltage of a voltage detector for the electric train line of a dc. system electric train with a standard voltage, and controlling the switching of the taps of a tap selecting transformer in loading on the basis of the deviation output, thus compensating the voltage drop of the electric train line. CONSTITUTION:When the voltage of an electric train line 5 lowers because of the operation of an electric train, in rush hour in heavy loaded state, a matching circuit 17 generates the output due to the deviation from a standard voltage. A tap selection controller 16 selects the tap position on the basis of the deviation output so that the output voltage of a tape selecting transformer 13 increases in loaded state, and performs the switching to the selected tap position. Therefore, the output voltage of a silicone rectifier 2 increases, and the voltage drop of the electric train line 5 is compensated, and a proper voltage can be always maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a power supply device for a DC electric railway, and more particularly to a DC power supply device that compensates for a drop in feeder voltage.

B6 Summary of the Invention The present invention provides a power supply device for a DC electric railway that converts AC power derived from an AC power source into DC power using a rectifier and supplies the DC power to a calculator line, in which a load is applied to an electric line connecting the AC power source and the rectifier. By inserting an on-load tap-changing transformer, matching the voltage of the overhead contact line with a predetermined reference voltage, and switching the tap of the on-load tap-changing transformer based on the deviation signal, This system compensates for the voltage drop in the line so that the overhead line voltage can always be maintained at an appropriate level.

C0 Conventional Technology In general, power supply devices for DC electric railways are configured to convert AC power derived from an AC power supply into DC power using a rectifier, and then supply the DC power to each contact line via a DC circuit breaker. . An example of such a power supply device is shown in FIG. In FIG. 2, AC power from an AC power supply 1 is converted to DC power by a silicon rectifier 2 without an output voltage control function.

The DC output power of the silicon rectifier 2 is transmitted to the electric car 6a via the DC positive bus 3, the DC high-speed circuit breaker 4a, and the contact line 5.
6b, respectively.

D0 Problems to be Solved by the Invention In the device configured as described above, the silicon rectifier 2 does not have an output voltage control function, so the output voltage vO of the rectifier 2 is constant. Therefore, the voltage vl of the overhead contact line 5 varies depending on the operating conditions of the electric cars 6a and 6b. In other words, when the load is light, the contact line voltage ■l becomes a high voltage, and as the load becomes heavier, such as during rush hours, the voltage v
1 will decrease. As described above, with the power supply device as shown in FIG. 2, it is difficult to maintain normal operation of the electric vehicle by keeping the overhead line voltage at an appropriate voltage.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a DC power supply device that can always maintain the overhead line voltage at an appropriate voltage.

Means for Solving Problem E1 The present invention provides a power supply device for a DC electric railway, in which AC power derived from an AC power source is converted into DC power by a rectifier, and the DC power is supplied to overhead contact lines. and a voltage detector that detects the voltage of the overhead contact line, which compares the output voltage of this voltage detector with a predetermined reference voltage and calculates the deviation output. and a switching tap control section that performs tap switching control of the on-load tap switching transformer based on the following.

20 Effects In the device configured as described above, the output voltage of the AC power source is transformed to a predetermined voltage by the on-load tap change transformer, and then converted to DC voltage by the rectifier. The DC output voltage of this rectifier is applied to the overhead contact line. When the contact line voltage fluctuates, the switching tap control section switches the taps of the on-load tap switching transformer in accordance with the variation.

Thereby, the output voltage of the on-load tap-changing transformer is adjusted to compensate for the voltage drop in the overhead contact line, and the overhead line voltage is maintained at a proper value.

G. Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In FIG. 1, the same parts as in FIG. 2 are shown with the same reference numerals, and the explanation thereof will be omitted. A silicon rectifier 2 is connected to the AC power supply bus 11 through an AC breaker 12 and an on-load tap switching transformer 13″f in series.The DC output power of the silicon rectifier 2 is connected to the DC positive bus 3 and the DC high speed It is supplied to the overhead contact line 5 via the circuit breaker 4a, and to the busbar 3 and the DC high speed circuit breakers 4b, 4c.

4d to other contact lines (not shown).

A voltage detector 15 is connected between the overhead contact line 5 and the rail 14. The detected voltage of this voltage detector 15 is supplied to a matching circuit 17 of a switching tap control device 16. This matching circuit 17 connects the output voltage of a reference voltage setter (not shown) that sets a predetermined reference voltage to the voltage detector 1.
Match the detected voltage in step 5. The deviation output of the matching circuit 17 is amplified by an amplifier 18 and then inputted to a tap selection circuit 19. The tap selection circuit 19 generates a signal for selecting the tap of the transformer 13 based on the output signal of the amplifier 18, and sends the tap selection signal to the tap drive circuit 20. The tap drive circuit 20 is connected to the transformer 13
A drive signal is generated for switching the tap to the tap selected by the tap selection circuit 19. Tap drive circuit 2
The zero output signal is supplied to the on-load tap-changing transformer 13 via the output circuit 21 . These matching circuits 17° amplifier 18. Tap selection circuit 19. Tap drive circuit 20
The switching tap control device 16 is composed of the output circuit 21 and the output circuit 21 . Note that the negative side output terminal of the silicon rectifier 2 is connected to the rail 14.

Suppose that the voltage of the overhead contact line 5 drops due to the operation of an electric car (not shown) during rush hours when the system is under heavy load, for example, in the apparatus configured as described in 5 above.

Then, the matching circuit 17 outputs a deviation output from the reference voltage. Switching tap control device 1 based on this deviation output
6 selects a tap position where the output voltage of the on-load tap change transformer 13 becomes high, and switches to the selected tap position.

As a result, the output voltage of the silicon rectifier 2 increases, and the voltage drop of the overhead contact line 5 is compensated for.

It is assumed that the reference voltage input to the matching circuit 17 is set arbitrarily. Moreover, the switching tap control device 16
is not limited to the configuration shown in FIG. 1, but may be configured using other circuits having the same function.

Effects of the H0 Invention As described above, according to the present invention, the following effects can be obtained. That is, (1) voltage drop in the overhead contact line can be compensated for and the voltage can always be maintained at an appropriate level.

(2) Due to the reason stated in item (1) above, normal and smooth operating conditions of the electric vehicle can be ensured.

(3) Effective use of electric power can be achieved due to the reason mentioned in (1) above.

(4) Since the power supply voltage is adjusted by the on-load tap switching transformer, there is no need to use a thyristor rectifier with an output voltage control function. Therefore, the entire device is inexpensive.

(5) Better power factor and efficiency than conventional voltage control systems using thyristor rectifiers.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of a conventional power supply device. 2... Silicon rectifier, 5... Tram line, 11...
AC power supply bus, 13...Tap switching transformer on load, 1
5... Voltage detector, 16... Switching tap control device,
17... Matching circuit, 18... Amplifier, 19.
...Tap selection circuit, 20...Tap drive circuit, 21
...Output circuit.

Claims (1)

[Claims] In a power supply device for a DC electric railway that converts AC power derived from an AC power source into DC power using a rectifier and supplies the DC power to overhead contact lines, a load tap inserted in an electrical path connecting the AC power source and the rectifier. A switching transformer, a voltage detector that detects the voltage of the overhead contact line, and comparing the output voltage of this voltage detector with a predetermined reference voltage, and detecting the voltage of the tap switching transformer at the time of load based on the deviation output. A DC power supply device comprising: a switching tap control section that performs tap switching control.