JPH0675867U - DC feeding voltage compensator - Google Patents

Abstract

(57) [Summary] [Purpose] The load current is detected without detecting the DC feed voltage, and the DC feed voltage is compensated at high speed. [Configuration] The rated current setting from the rated current setting device 9 and the load current from the direct current detector 8 are compared, and when the load current exceeds the rated current setting, this is detected at high speed by the high gain amplifier 12, The limiter causes the integrating amplifier to output a predetermined voltage command, causes the thyristor rectifier 2 to output a predetermined output via the circuits 13 to 17, and quickly compensates the DC feeding voltage output from the silicon rectifier 1. When the load current exceeds 300% of the rated current setting, the current of the thyristor rectifier is detected by CT ₁ and CT ₂ and the thyristor current rectified by the rectifier 5 is input, and the comparator 18 of 300% setting outputs a thyristor rectifier stop command. Stop voltage compensation.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a DC feeder voltage compensator for use in series with a silicon rectifier in a DC electric railway substation to keep the feeder voltage constant.

[0002]

[Prior art]

 Conventionally, a DC feeding voltage compensator (hereinafter referred to as DCVR a circuit is shown in FIG. 3. In FIG. 3, 1 is a three-phase transformer TF.₁DC thyristor rectifier, which is connected to the silicon rectifier 1 in series and compensates for the output voltage of the silicon rectifier 1 decreasing due to the load current, _S Is a bypass diode connected in parallel with the thyristor rectifier 2.

The thyristor rectifier 2 is controlled by amplifying the deviation between the voltage command from the voltage setting device 3 and the feeding voltage value from the DC voltage detector 4 by the voltage control amplifier 11, and the phase pulse by the phase control circuit 14. The gate of the thyristor element of the thyristor rectifier 2 is controlled through the gate oscillation circuit 15, the pulse transformer 16 and the gate circuit 17, and the silicon rectifier output voltage A + the thyristor rectifier output voltage B is rated as shown in FIG. The current I _S is controlled to be constant in the range.

Reference numeral 7 is a current limiter circuit for applying a limiter to the voltage control amplifier 11, which is a current transformer CT. ₁ , CT₂The thyristor rectifier current obtained by rectifying the input current of the thyristor rectifier 2 detected by the rectifier 5 is input to the comparator 6 of the 100% current (rated current) set, and the thyristor rectifier current is the maximum allowable current value (rated current) I_SWhen the voltage exceeds I, a limiter is applied to the voltage control amplifier 11, and as shown in FIG._SWith the above, the output voltage is reduced.

In addition, since the thyristor rectifier 2 of the DCVR is connected in series with the silicon controller 1 and is always energized, the thyristor rectifier 2 becomes large. In order to reduce the size of the thyristor rectifier 2, as shown in FIG. 5, a method is considered in which the thyristor rectifier 2 operates when a load larger than the rated current I _S is taken in.

[0006]

[Problems to be solved by the device]

 In the above DC feeding voltage compensator, the feeding voltage is detected and fed back by the DC voltage detector 4, but the response time of this DC voltage detector 4 is 0.3 sec, which is considerably long and the voltage control amplifier 11 has a long response time. There is no choice but to lengthen the time constant.

When the power running vehicle enters the feeding section of the substation, or when the vehicle in the feeding section starts, or when the coasting mode is switched to the power running mode, a large rising current flows. Since the time constant of the voltage control amplifier 11 is long and the response is slow, the output voltage of the thyristor rectifier 2 cannot follow the movement of the load current and is greatly reduced, and the time until the output voltage returns to the beginning becomes long.

The present invention has been made in view of the above-mentioned problems of the related art, and an object thereof is to eliminate the use of a feedback slow response when a load larger than the rated current is taken in. It is an object of the present invention to provide a DC feed voltage compensator capable of compensating feed voltage at high speed by current control.

[0009]

[Means for Solving the Problems]

 In order to achieve the above object, the DC feeding voltage compensator according to the present invention compares the first current setting value with the load current value and confirms that the load current value is larger than the first current setting value. The thyristor rectifier current value is compared by comparing a control circuit that detects with high sensitivity and outputs a predetermined voltage to the thyristor rectifier with a second current setting value that is 2 to 4 times larger than the first current setting value. Is provided with a comparator that outputs a thyristor rectifier stop command when exceeds the second current setting value.

[0010]

[Operation] The control circuit compares the first current setting value and the load current value, and when the load current value becomes higher than the first current setting value, detects this with high sensitivity and outputs a predetermined voltage of the thyristor. High-speed compensation of DC feeding voltage. Therefore, even if the load current increases rapidly, the voltage can be compensated without delay.

The comparator compares the second current setting value with the thyristor rectifier current value, outputs a thyristor rectifier stop command when the thyristor rectifier current value exceeds the second current setting value, and stops feeding voltage compensation. Eliminates an increase in load current due to voltage compensation.

[0012]

【Example】

 FIG. 1 shows a circuit of a DC feeding voltage compensator. In the figure, the same components as those shown in FIG. 3 of the related art are designated by the same reference numerals and their duplicate description will be omitted.

In FIG. 1, 8 is a direct current detector for detecting the load current I, 9 is a rated current setter, 12 is a current command (−) from the rated current setter 9 and a negative current from the direct current detector 8. high gain amplifier for amplifying the difference between the load current value (+), 13 high-gain amplifier 12 in with the limiter via the connected diodes D ₁ through the diode D ₁ forces out to the phase control circuit 14 integrating amplifier Then, this limiter is adjusted so as to limit the output voltage of the thyristor rectifier 2 to 200V.

Reference numeral 18 denotes a thyristor rectifier 2 that detects the input current of the thyristor rectifier 2 by rectifying the outputs of the current transformers CT ₁ and CT ₂ with the rectifier 5 and outputs the thyristor rectifier current of 300% when the detected current exceeds 300% of the rated current. A current setting comparator, Ry ₁ is a thyristor rectifier stop command relay that is turned on by the output of the comparator 18. Other configurations are the same as those of the conventional FIG.

Next, the operation of this embodiment will be described. Until the load current I reaches the rated current I _S , the difference between the current command from the rated current setting device 9 and the load current from the DC current detector 8 is negative, and the high gain amplifier 12 does not work, so the thyristor does not work. The rectifier does not output. Therefore, the feeding voltage is the output voltage from the silicon rectifier 1.

When the load current I reaches the rated current I _S , the difference between the detected load current and the rated current command becomes positive, and the output of the high-gain amplifier 12 becomes “L”, which is connected via the diode D _1. A voltage command is output from the integrating amplifier 13 with limiter to the phase control circuit 14 via the diode D ₂ , and the gate of the thyristor element of the thyristor rectifier 2 is output via the gate oscillator circuit 15, the pulse transformer 16 and the gate circuit 17. Control. At this time, the limiter of the integrating amplifier 13 is set so as to limit the output voltage B 2 of the thyristor rectifier 2 to 200V, so the thyristor rectifier outputs the output voltage B of 200V as shown in FIG. 2 to compensate the feeding voltage. To do.

When the thyristor rectifier current exceeds 300% of the rated value, the comparator 18 with a current setting of 300% outputs the thyristor rectifier stop command relay Ry1 to turn on the thyristor rectifier 2. Therefore, the output voltage B of the thyristor rectifier 2 disappears, and only the output voltage A of the silicon rectifier 1 remains. That is, the thyristor rectifier 2 outputs the voltage B in the range of 100% to 300% of the rated current to compensate for the decrease in the output voltage A of the silicon rectifier.

In the embodiment, the electric voltage is compensated by 200 V in the range of 100% to 300% of the rated current, but the invention is not limited to this. Needless to say, the circuit may be changed appropriately.

[0019]

[Effect of device]

 Since the DC feeding voltage compensator of the present invention is configured as described above, it has the following effects.

(1) Since the current control system uses a high gain amplifier that does not use voltage feedback using a DC voltage detector with a slow response, it is possible to compensate the feeding voltage with a fast response.

(2) Parts such as a DC voltage detector are not required, and the control circuit can be configured with a small number of parts.

(3) Since the thyristor rectifier operates when the load current exceeds the set current, it can be miniaturized.

(4) Therefore, the device can be made compact and low cost.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a load current-output voltage characteristic diagram in the example.

FIG. 3 is a circuit diagram showing a conventional example.

FIG. 4 is a load current-output voltage characteristic diagram in a conventional example.

FIG. 5 is a characteristic diagram showing another example of feeding voltage compensation.

[Explanation of symbols]

 1 ... Silicon rectifier 2 ... Thyristor rectifier 3 ... Voltage setting device 4 ... DC voltage detector (DCPT) 5 ... Rectifier 6, 18 ... Comparator 7 ... Current limiter circuit 8 ... DC current detector (Hall CT) 9 ... Rated current setting 11 ... Voltage control amplifier 12 ... High gain amplifier 13 ... Phase control circuit 15 ... Gate oscillation circuit 16 ... Pulse transformer 17 ... Gate circuit

Claims (1)

[Scope of utility model registration request] 1. A thyristor rectifier is connected in series to a silicon rectifier that outputs to a DC feeder, and the thyristor rectifier is controlled to compensate for the DC feeder voltage. And a control circuit that outputs a predetermined voltage to the thyristor rectifier by detecting with high sensitivity that the load current value is greater than the first current setting value, and a thyristor rectifier current value that is equal to the first current setting value. 2 to
A comparator that outputs a thyristor rectifier stop command when the thyristor rectifier current value exceeds the second current setting value by comparing with the second current setting value that is four times larger, and supplies the feeding voltage without using voltage feedback. Compensation device for DC feeding voltage characterized by compensation.