JPH0688508B2 - Control method and apparatus for regenerative inverter for electric railway - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a converter for supplying DC power to a trolley line of a DC feed electric railway and a regenerative power generated by an electric vehicle capable of regenerative control on an AC power supply side. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative substation system including a regenerative inverter, and more particularly to a control method and apparatus for a regenerative inverter for electric railways.

B. SUMMARY OF THE INVENTION The present invention provides a control method and apparatus for a regenerative inverter for electric railways, which detects a converter current, an inverter current, and an electric line voltage, and provides the detected electric quantity and a preset predetermined electric quantity. In addition, the converter input voltage fluctuations are configured even when the electric vehicle is in the power running mode by configuring the automatic voltage adjustment system of the electric line voltage based on the deviation output obtained by the above-mentioned matching. In this way, the inverter can be surely brought into the operating state regardless of the above, and the circulating current flowing in the inverter can be always suppressed to the minimum level.

C. Conventional Technology Generally, a regenerative substation system is configured as shown in FIG. 3, for example. In FIG. 3, the output power of the AC power supply 1 is input through a transformer 2a to a converter 3 configured by connecting diodes in a bridge. The combo unit 3 converts the input AC power into DC power, and supplies the DC power to the electric vehicle 6 via the DC high-speed circuit breaker 4a and the train line 5. Regenerative electric power generated during the regenerative operation of the electric vehicle 6 is input via a DC high-speed circuit breaker 4b and a DC reactor 7 to an inverter 8 configured by connecting a thyristor in a bridge. The inverter 8 converts the input DC power into AC, and regenerates the AC power to the AC power supply 1 via the transformer 2b.

In the device configured as described above, the operation control of converter 3 and inverter 8 is performed as shown in the voltage-current characteristic diagram of FIG. 4 in accordance with the change in voltage Ed of train line 5. That is, when the electric vehicle 6 is in the powering operation, the converter 3
When only DC current is Id, the voltage Ed of the electric train line 5 at that time changes as shown in the region I of FIG. Further, when the electric vehicle 6 performs regenerative braking, the voltage Ed of the train line 5 rises, and when the voltage Ed exceeds the regenerative set voltage, an inverter control circuit (not shown) allows the inverter 8 to operate.
The operation of is started. Then, the inverter 8 is subjected to constant voltage control by the inverter control circuit so that the voltage Ed of the electric line 5 is kept at the electric line voltage Vd ₀ at the time of regeneration as shown in the regenerative operation region II of FIG.

D. Problems to be solved by the invention In the regenerative substation system configured as described above,
If the no-load DC voltage of the inverter is set lower than the maximum train line voltage Vd (no-load DC voltage of the converter) during the power running, the converter 3 is affected by fluctuations in the converter input voltage.
An excessive circulating current will flow between the inverter and the inverter 8.
Therefore, as shown in FIG. 4, it is necessary to set the regenerative set voltage Vd ₀ higher than the maximum train line voltage Vd during power running. However, in such a setting, even if the electric car 6 performs regenerative braking, the inverter 8 remains in the non-operating state until the train line voltage reaches the regenerative set voltage from the maximum train line voltage Vd during power running. stand by. Therefore, the regenerative electric power generated by the electric vehicle 6 cannot be regenerated, and thus the regenerative electric power cannot be effectively used. In particular, if the rise of the regenerative current during regenerative braking is fast and the operation of the inverter 8 is delayed as described above, the voltage Ed of the train line 5 rises abnormally. Therefore, the electric vehicle 6 may use regenerative braking. It becomes impossible to stop the circuit breaker on the electric vehicle side by using an air brake or the like after tripping.

In addition, the following inverter control method has been used in order to solve the above-mentioned drawbacks. That is, as shown in the voltage-current characteristic diagram of FIG. 5A, when the voltage of the electric power line 5 is a predetermined value, for example, Ed ₀ or more, the inverter 8 is operated at the control advance angle γ ₀ to operate the converter 3 and the inverter 8. This is a control method in which a predetermined circulating current is made to flow in the meantime, and when the train line voltage is equal to or higher than a predetermined value, the inverter 8 is controlled to a constant voltage to keep the train line voltage at a constant value, for example, Vd ₁ . By controlling the inverter 8 in this manner, the inverter can be kept in operation even when the electric vehicle is in the power running mode.
The switching from the power running operation to the regenerative operation can be performed quickly and smoothly, which can suppress an excessive circulating current and an abnormal voltage rise in the electric power line. However, according to such a control method, when the converter input voltage (commercial power supply voltage) fluctuates as shown in FIG.
_The following problem occurs depending on what voltage value the voltage (Ed ₀ ) at the start of constant control by ₀ is set to. That is, the voltage at the start of γ ₀ constant control is set to Ed ₀₁ , and predetermined γ ₀ constant control is performed, and the train line voltage is set to A in FIG. 5 (b).
In the case of the characteristics, for example, it is assumed that the converter input voltage reaches the lowest level. In this case, as is clear from the characteristic diagram of FIG. 5 (b), it becomes impossible to keep the inverter 8 in operation by supplying a predetermined circulating current when the converter 3 is in operation. For example, when switching to regenerative operation. The operation of the inverter 8 is delayed and the train line voltage abnormally rises. In order to eliminate the above-mentioned drawback, the voltage at the start of constant γ ₀ control is set to Ed _02, which is lower than Ed ₀₁ , as shown in Fig. 5 (b).
It is assumed that the electric line voltage is controlled as shown by the B characteristic of. In this case, if the converter input voltage reaches the maximum level, the circulating current increases, which is uneconomical.

The present invention has been made in view of the above points, and can reliably operate the inverter regardless of fluctuations in the converter input voltage even when the electric vehicle is in the powering operation, and the circulating current flowing in the inverter. It is an object of the present invention to provide a control method and an apparatus for a regenerative inverter for electric railway that can always suppress the power consumption to the minimum level.

E. Means for Solving the Problems The present invention includes (1) a converter that converts AC output power of an AC power supply into DC and supplies the DC power to a train line of a DC type electric railway, and an electric car during regenerative braking. In a regenerative substation equipped with an inverter that regenerates regenerative power to the power supply side,
Phase control of the inverter is performed based on a deviation output between the train line voltage and a predetermined regenerative setting voltage, and a deviation output between a sum of currents flowing through the converter and the inverter and a predetermined circulating current setting amount is a predetermined amplification characteristic. In addition to the amplification, the regenerative setting voltage is corrected based on the amplified output, and when the current flowing through the converter is smaller than a predetermined converter setting current, the regenerative setting voltage is not corrected. (2) A converter for converting the AC output power of the AC power supply into a DC power, and supplying the DC power to the trolley line of the DC electric railway, and the regenerative power generated by the electric car during regenerative braking to the power supply side. In a regenerative substation equipped with a regenerative inverter,
A first matching section for matching the current flowing through the converter with the current flowing through the inverter and a predetermined circulating current setting amount; and a second matching section for matching the current flowing through the converter with the predetermined converter current setting amount. ,
An amplifying section for amplifying the deviation output of the first matching section with a predetermined amplification characteristic; a third matching section for matching the output of the amplifying section with the train line voltage and a predetermined regenerative voltage setting amount; Based on the deviation output of the third butt section and the switch section which is inserted in the electric path connecting the third butt section and the amplification section and which is on / off controlled based on the deviation output of the second butt section. And a control unit that controls the phase of the inverter.

F. Action In the control method described above, it is assumed that the sum of the currents flowing through the converter and the inverter during the power running operation of the electric vehicle is larger than the predetermined circulating current set amount. In this case, the regenerative set voltage is corrected to be high, so that no circulating current flows in the inverter. Next, it is assumed that the sum of the currents flowing through the converter and the inverter during the power running operation of the electric vehicle becomes smaller than a predetermined circulating current set amount. In this case, the phase control of the inverter is started and a predetermined circulating current flows through the inverter. Next, it is assumed that the current flowing through the converter during the regenerative operation of the electric vehicle becomes smaller than the predetermined converter set current. In this case, the correction of the regenerative set voltage is not performed, whereby the inverter performs constant voltage control so that the train line voltage becomes the regenerative set voltage.

Further, in the control device as described above, it is assumed that the current flowing through the converter and the inverter during the power running operation of the electric vehicle is larger than a predetermined circulating current set amount. In this case, since the signal obtained by amplifying the deviation output of the first matching unit by the amplification unit is input to the third matching unit, the regenerative setting voltage is corrected to be high. Therefore, no circulating current flows through the inverter. Next, it is assumed that the current flowing through the converter and the inverter during the power running operation of the electric vehicle becomes smaller than a predetermined circulating current setting amount. In this case, the amplification section sends a correction signal to the third matching section so that the sum of the currents flowing through the converter and the inverter becomes equal to the circulating current setting amount.
Therefore, the control unit starts the phase control of the inverter.
A predetermined circulating current flows through the inverter. Next, it is assumed that the current flowing through the converter during the regenerative operation of the electric vehicle becomes smaller than the predetermined converter set current. In this case, since the switch unit is off-controlled based on the deviation output of the second matching unit, the third matching unit outputs the deviation between the train line voltage and the predetermined regenerative setting voltage. As a result, the control unit controls the phase of the inverter so that the train line voltage becomes the regenerative setting voltage.

G. Example Hereinafter, one example of the present invention will be described with reference to the drawings. In FIG. 1, the same parts as those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted. Transformer 2a and converter 3
A current transformer 11 is inserted in the electric path connecting the two, and a current transformer 12 is inserted in the electric path connecting the transformer 2b and the inverter 8. Current transformer 12
The AC output current is converted into DC by the AC / DC converter 13 and then introduced into the first matching circuit 14. The AC output current of the current transformer 11 is converted to DC by the AC / DC converter 15, and then the first matching circuit 14 and the second matching circuit 16 are connected.
Will be introduced to. The first matching circuit 14 is provided with the circulating current setting value previously set by the circulating current setting device 17 and the converter 13
And the output current of the converter 15 are matched. The second matching circuit 16 is provided with a converter which is previously set by the converter current setting unit 18 and the set current and the converter.
Match with the output current of 15. First match circuit 14
The deviation output of is amplified by the amplifier 19 having a predetermined amplification characteristic. The amplifier 19 outputs a positive output signal when the sum of the converter current and the inverter current is larger than the circulating current set value, as shown in the characteristic curve in the figure. Also the amplifier
When the sum of the converter current and the current of the inverter is smaller than the circulating current set value, 19 issues a correction signal for making the sum of the currents equal to the circulating current set value. amplifier
The output of 19 is a diode 21 of the polarity shown and an analog switch
It is introduced into the third matching circuit 22 via a parallel circuit consisting of 20. Reference numeral 24 is a DC / DC converter for detecting the voltage of the train line 5, and the output voltage of the converter 24 is introduced into the third matching circuit combination 22. The third matching circuit 22 matches the regeneration setting voltage preset by the regeneration voltage setting device 23, the output signal of the amplifier 19 and the output voltage of the converter 24. The deviation output of the third matching circuit 22 is supplied to an automatic voltage adjusting circuit 25 including a phase shifter 27 and a gate circuit 28. The automatic voltage adjusting circuit 25 controls the phase of the inverter 8 according to the output signal of the third matching circuit 22. The deviation output of the second matching circuit 16 is the comparator 26.
And an open / close control signal is supplied to the analog switch 20 based on the operation of the comparator (-CP) 26. The set current is the set current of the circulating current setter 17 (Ijset)> the set current of the comparator current setter 18 (I _CN se
t) is set in advance, for example Ijset
Set 100 amps and I _CN set to 0 to several amps respectively.

Next, the operation of the device configured as described above will be described with reference to the voltage / current characteristic diagram of FIG. First, during the power running operation of the electric vehicle 6, the power running power is supplied by the converter 3, and at this time, the voltage of the train line 5 changes according to the characteristics shown in the power running region of FIG. In this case, the output current (current proportional to the current flowing through the converter 3) A of the AC / D converter 15 is the set current I _CN set of the converter current setter 18.
Since it is larger, the output of the comparator 26 (-CP) becomes "L" level and the analog switch 20 is turned on.
At this time, since the output current A of the converter 15 is larger than the set current Ijset of the circulating current setting device 17, the amplifier 19 sends the positive output signal C to the third matching circuit 22 via the analog switch 20. Therefore, the set voltage of the regenerative voltage setting device 23 is corrected and raised to a value of _VDC set + C. As a result, the inverter 8 operates so that no circulating current flows.

Next, the current flowing through the converter 3 decreases and the output current A of the AC / DC converter 15 <the setting current Ijse of the circulating current setting device 17
Let's say you have a relationship. Then, the amplifier 19 issues a correction signal so that the sum of the currents flowing through the converter 3 and the inverter 8 becomes equal to the circulating current setting amount (Ijset = A + B). Therefore, the automatic voltage adjusting circuit 25 controls the phase of the inverter 8 based on the output of the third matching circuit 22. As a result, a circulating current flows through the inverter 8 as shown in FIG. Here, the train line voltage Ed at which the circulating current starts to flow is switched according to the converter input voltage fluctuation (commercial power supply voltage fluctuation). That is, as shown in FIG. 2, Edc is used when the converter voltage is the lowest input voltage Vc, Edb is used when the converter input voltage is the rated input voltage Vb, and Eda is used when the converter input voltage is the highest input voltage Va.
Becomes When the converter input voltage fluctuates in this way, the control start voltage Ed for flowing the circulating current is switched accordingly, so that the circulating current flowing through the inverter 8 is controlled to be constant regardless of the converter input voltage. be able to. Now, for example, set the circulating current set value Ijset to 100.
(A) and power running current 10 (A), the current Ic flowing through the converter 3 is The current Ii flowing through the inverter 8 is Becomes

Next, it is assumed that the electric vehicle 6 performs regenerative operation and the current flowing through the converter 3 becomes zero. Then, the output current A of the converter 15 becomes smaller than the set current I _CN set of the setter 18, so that the output of the comparator 26 (-CP) becomes "H" level and the analog switch 20 is turned off. AC at this point
Since the output current (current proportional to the current flowing through the inverter 8) B of the / DC converter 13 has a relationship of B ≧ Ijset,
The output C of the amplifier 19 has a relationship of C ≧ 0. Therefore, the output C of the amplifier 19 is blocked by the diode 21 because the analog switch 20 is turned off. This makes the third
The matching circuit 22 uses the set voltage (V
_{The difference between the DC} set) and the output voltage of the DC / DC converter 24 (voltage proportional to the voltage of the train line 5) is output. Then, the automatic voltage adjusting circuit 25 controls the constant current of the inverter 8 so that the electric line voltage does not exceed the set voltage V _DC set as shown in FIG. As a result, the regenerative electric power generated by the electric vehicle 6 is smoothly regenerated.

As described above, even when the electric vehicle is in the power running mode, the inverter can be operated, and the inverter control start voltage can be changed to an appropriate value according to the fluctuation of the converter input voltage. Regardless of the magnitude of the voltage, the circulating current can be constantly controlled. The circulating current (Ij) and the converter current (I
Fig. 6 shows the relationship between c) and the inverter current (Ii).

H. Effects of the Invention As described above, according to the present invention, the following effects can be obtained. That is, (1) Even if the electric vehicle is in the power running mode and the commercial power supply voltage fluctuates, constant current control is performed to keep the circulating current constant, so that an excessive circulating current does not flow. Further, since the circulating current is small, energy saving can be achieved.

(2) Since the inverter operates even during the power running operation of the electric vehicle, it is possible to smoothly shift to the regenerative operation without causing an operation delay during the regenerative operation of the electric vehicle.

(3) Due to the reason of the above item (2), it is possible to suppress the abnormal voltage rise of the electric power line, and thus the safety of the electric vehicle is maintained.

(4) Since the electric vehicle can smoothly perform regenerative braking during regenerative operation, it is not necessary to use an air brake, and smooth operation can be continued.

(5) Since the electric power generated by the electric vehicle during regenerative operation can be quickly regenerated to the AC power source side, the regenerated electric power can be effectively used.

(6) The transition from regenerative operation to power running can be performed smoothly.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1, 2 and 6 show an embodiment of the present invention, FIG. 1 is a circuit diagram, FIG. 2 is a voltage / current characteristic diagram, and FIG.
Fig. 3 is a current characteristic diagram, Fig. 3 is a circuit diagram showing an example of a conventional regenerative substation system, Fig. 4 and Fig. 5 (a), (b).
3A and 3B are voltage / current characteristic diagrams for explaining a conventional control pattern. 1 ... AC power supply, 3 ... Converter, 5 ... Train line, 6
...... Electric train, 8 …… Inverter, 14,16,22 …… Collecting circuit, 17 …… Circulating current setting device, 18 …… Converter current setting device, 19 …… Amplifier, 20 …… Analog switch, 23 ・ ・ ・
… Regenerative voltage setting device, 25 …… Automatic voltage adjustment circuit, 26 …… Comparator.

Claims (2)

[Claims] 1. A converter for converting the AC output power of an AC power supply into a DC power, and supplying the DC power to the trolley line of a DC electric railway, and an inverter for regenerating the regenerative power generated by an electric car during regenerative braking to the power supply side. In a regenerative substation equipped with, a phase control of the inverter based on the deviation output of the train line voltage and a predetermined regenerative setting voltage, the sum of the current flowing through the converter and the inverter and a predetermined circulating current set amount Amplifies the deviation output with a predetermined amplification characteristic, corrects the regenerative setting voltage based on the amplified output, and when the current flowing through the converter is smaller than a predetermined converter setting current, A control method for a regenerative inverter for electric railways, characterized in that correction is not performed. 2. A converter for converting the AC output power of the AC power supply to DC and supplying the DC power to the trolley line of a DC electric railway, and an inverter for regenerating the regenerative power generated by an electric car during regenerative braking to the power supply side. A regenerative substation comprising: a first reciprocal substation for correlating a current flowing through the converter, a current flowing through the inverter, and a predetermined circulating current set amount;
A matching section, a second matching section for matching the current flowing through the converter with a predetermined converter current setting amount, an amplifying section for amplifying the deviation output of the first matching section with a predetermined amplification characteristic, and this amplifying section. A third matching section for matching the output of the section, the train line voltage, and a predetermined regenerative voltage setting amount, and a second matching section inserted in a circuit connecting the third matching section and the amplifying section. A switch unit that is on / off controlled based on the deviation output of
A control unit for a regenerative inverter for electric railway, comprising: a control unit that controls the phase of the inverter based on the deviation output of the butting unit.