JPS5933717Y2 - DC electric railway power supply equipment - Google Patents

Description

[Detailed description of the invention] This invention relates to a power supply system for DC electric railways, and in particular, a substation that can regenerate regenerated power to the commercial frequency power supply bus by operating a Sirisk rectifier serving as a DC power source as a separately excited inverter. The present invention aims to provide a power supply device that, when applied to a substation, can reduce the equipment, etc. of the substation.

In power supply systems for DC electric railways, SiRISC rectifiers are being used instead of silicon rectifiers as forward power converters in order to improve protection coordination in the event of an accident and to perform highly accurate voltage regulation.

Furthermore, we installed a regenerative inverter at the substation that regenerates the regenerated power from the vehicle during regenerative operation to the commercial frequency power bus side of the AC input power source to effectively use the power, and we also applied a power supply device that is in line with the energy saving trend. It is being done.

The problem with this type of power supply device is the thyristor rectifier,
Since expensive power equipment such as thyristor circuit breakers and regenerative inverters are installed, the equipment cost itself becomes extremely uneconomical.

Therefore, a type of substation has also been proposed in which a silice rectifier, which is a DC power source, also performs a power regeneration function, and a regeneration inverter is omitted.

Figure 1 shows a typical low-cost type power supply device, in which 1 is a commercial frequency power supply for AC input power supply, and 2 is a power supply for stepping down the AC input power supply voltage to an appropriate value. In the transformer, 3 is a Sirisk rectifier as a forward power converter that converts AC input power into DC power, 4 is a DC positive bus that supplies the required DC power to the feeder lines of multiple lines, and 5 is a negative bus. show.

DI-D2 is a stopper diode that provides the required power (DC power) to the vehicle when the sirisk rectifier in step 3 is operating as a converter.
2 is a thyristor switch for regenerating regenerative power (regenerative power) from a regenerative vehicle to the commercial frequency power supply bus side during regenerative operation when the thyrisk rectifier in 3 is operating as an inverter, and H8 and -H82 are This is a DC high speed circuit breaker.

Since the operation of the power supply device constructed in this manner is well known, only the problems of the conventional device shown in FIG. 1 will be described here.

The conventional device shown in Fig. 1 operates the thyrisk rectifier as a separately excited inverter by cooperating with the thyristor rectifier 3 and the thyrisk switches 81-82 cross-connected to the main circuit, and the stopper diodes D1-D2. This power supply device has the characteristics of a power supply device in that it regenerates the regenerated power from the power source to the commercial frequency power supply bus side and eliminates the regeneration inverter, but this power supply device poses a new problem during regenerative operation.

That is, the feeder voltage during converter operation, in which the silice rectifier operates as a converter and supplies the required power to the load, is normally maintained at 1500 (V).

Here, if the voltage drop of the thyristor rectifier is approximately 90 (V) and the conversion system of the rectifier is 1.35, then the secondary voltage of the power transformer ■2 is ■22 1500 + 9071.3
It becomes 51180 (V).

Further, the no-load DC voltage Edo is Edo=1180X1.
35=1590 (V).

This no-load DC voltage Edo is taken as the rated DC voltage of the inverter when the thyristor rectifier performs reverse conversion operation, and when the DC voltage of the rough wire reaches approximately 1530 (V), the thyristor rectifier operates in the reverse conversion region. The timing of switching between the converter and the inverter is regulated in advance so that the converter and the inverter are switched.

Therefore, there is a regenerative vehicle, and the DC voltage of the electric wire is approximately 1530
(V), the control advance angle γ of the thyristor rectifier is automatically switched from converter operation to inverter operation, and thereafter the DC voltage of the feeder line maintains the inverter's rated DC voltage Ed = 1590 (V). The regenerative power regenerated to the commercial frequency power supply side is appropriately controlled on the inverter side so as to

In this way, during regenerative operation, the DC voltage of the feeder line is approximately 159
0 (V), but during such regenerative operation, for example, if the regenerative vehicle is located far away from the power supply device shown in FIG. If a power regeneration resistor device that absorbs regenerated power is installed at a location and the regenerative vehicle is located far away from the adjacent substation, the power regeneration resistor device that absorbs the regenerated power Current power from the adjacent substation flows into the substation, and as a result, the feeder line voltage was maintained at approximately 1590 (V) by the combination of the power regeneration resistor and the inverter. As a result, the voltage increases to approximately 1 s o (V).

Such abnormal voltage increases in feeder lines are likely to occur especially when regenerative vehicles drive on slopes, etc., but the inverter must have voltage resistance characteristics and operational performance that are sufficient to withstand this abnormal voltage. However, if the DC voltage of the electric wire on the regenerative vehicle side rises to 1800 (V), and the specified operation to throttle down the regenerative power is delayed for some reason, the inverter will become overloaded, commutation will fail, and it will become inoperable. It goes in.

As described above, the conventional device shown in Fig. 1 has operational instability in that commutation failure occurs when overload occurs during regeneration, and furthermore, each device of the power supply device including the Cyrisk rectifier Even if the DC voltage of the feeder line rises to a high voltage of 18 oo (v), it must have enough withstand voltage and capacity to withstand, and as a result, the equipment cost of the power supply device itself will rise significantly. Considering these factors, the advantage of a power supply system is that it is possible to reduce power consumption through regenerative operation by assigning an inverter function to the Sirisk rectifier and regenerating regenerated power to the power supply side. It is a matter of being lost.

The present invention has been devised in view of this point, and in particular, the present invention provides overload protection for the inverter by providing cross-connected thyristor switches with the function of cutting off regenerative current. This system is characterized by solving problems such as withstand voltage of equipment including rectifiers, and will be described in detail based on the embodiment shown in FIG. 2 above.

In the embodiment of FIG. 2, the same parts as in FIG. If it responds to current, sensors that combine a DC transformer and shunt resistor, as well as sensors such as photodetectors that apply Hall elements, Faraday effects, Pockels effects, etc., are used. If the regenerative voltage is to be detected, one of the voltage detection sensors, such as one based on resistor voltage division or one based on capacitor voltage division, is applied.

7 is a forced extinguishing circuit for forcibly extinguishing the thyrisk switch using a signal from the detection element, and as shown in the figure, this circuit includes an auxiliary thyristor that is activated by a signal from a control device (not shown); When the polarity of the charged charge is determined in advance by the capacitor C, and when the cyrisk switch is turned off,
It is constructed with a glue handle L to apply a reverse bias for a required period of time to ensure that the central junction J2 of the thyrisk switch regains its forward blocking ability.

Now, to describe the operation of this embodiment configured as described above,
During power operation in which the Cyrisk rectifier 3 operates in the converter region, the Cyrisk switches 51S2 are each turned OFF.
In the state, commercial frequency power supply 1 → transformer 2 → Sirisk current generator 3 → stopper diode D1 → DC positive electrode bus 4
→ DC high-speed circuit breaker H81 or H82 → Feeder wire (not shown) → Motor vehicle (not shown) → DC negative electrode bus 5 → Stopper diode 1) Supply the required power to the motor vehicle through the path 1) drive

During such converter operation, when predetermined regenerative braking is performed to stop the moving vehicle, the regenerative power from the regenerative vehicle is transferred from the electric wire to the DC high-speed circuit breaker H8 (not shown).
, or H82→DC positive electrode bus 4→Sirisk switch S
1 → Thyristor rectifier 3 that operates as a separately excited inverter
→ Commercial frequency power supply → Transformer 2 → Cyrisk rectifier 3 → Cyrisk switch S2 → DC negative electrode bus 5 → Flows through a path of a regenerative vehicle (not shown).

During such regenerative operation, the feeding voltage is approximately 1530 (V) to 1
At the same time, the control advance angle γ of the thyrisk rectifier 3, which operates as a separately excited inverter, is controlled to maintain 590 (V), and at the same time, the detection element 6 detects the regenerative current flowing through the DC bus bar or the regenerative voltage (feeding voltage) between the bus bars. The signal from this detection element is guided to a control device (not shown) to monitor the voltage or current during regeneration.

During such regenerative operation, the regenerative power regenerated to the commercial frequency power supply side gradually increases, and as mentioned above, the regenerative vehicle is located at a considerable distance from the power supply device, and the power regeneration resistance device of the adjacent substation When power begins to flow in from the adjacent substation, these factors cause the DC feeder voltage, that is, the DC voltage between the DC positive bus and negative DC bus, or the DC current in the bus to reach the standard value. When this is determined by a control device (not shown), the auxiliary thyristor S of the forced arc-extinguishing circuit 7 is activated by a predetermined signal output from the control device.

When the charge is ignited and charged with the polarity shown, the charge is
Capacitor C → Auxiliary thyristor S.

81 is extinguished by the oscillating current generated in the process of discharging through the path of → Cyrisk switch S1 → Commutation reactor L. When the value of this oscillating current exceeds the value of the regenerative current that can pass through Cyrisk switch S1, the arc 81 is extinguished. Ru.

What is important when shutting off such regenerative current is that, for example, if the DC voltage between the busbars is to be monitored, in this application, the regenerative power is immediately turned off when the DC voltage reaches approximately 1650 (V) to 1700 (V). This is intended to reduce the operational responsibility of the sirisk rectifier during inverter operation and prevent unnecessary commutation failures.

That is, the system allows the regenerated power to be regenerated to the power source side to a certain extent, but when the regeneration progresses to a certain extent, the regenerated power is immediately cut off, and in parallel with this operation, the vehicle side performs an operation to reduce the regenerated power.

Therefore, according to the present application, various effects as shown below can be achieved.

(1) Since the regenerative power is cut off, the operational responsibility of the Sirisk rectifier operating as an inverter is reduced, and commutation failure of the Innovak can be reliably prevented due to overload during regenerative operation, making it extremely stable. It is possible to realize a power supply device with high performance.

(2) Based on the advantages mentioned above, it is possible to reduce the withstand voltage and capacity of the Sirisk rectifier, and also to reduce the capacity of the power transformer that is shared by the converter and inverter, providing a very economical power supply device. .

(3) Since the existing thyristor switch is used as the circuit breaker to cut off the regenerated power, a more economical device can be realized.

(4) Even if the regenerated power is cut off, a certain amount of the regenerated power is regenerated to the power source side, so it is possible to realize an energy-saving power supply device that is in line with the current trends from the standpoint of effective energy use.

[Brief explanation of drawings]

FIG. 1 is a specific circuit configuration diagram showing a conventional power supply device, and FIG. 2 is a specific circuit configuration diagram of a power supply device showing an embodiment of the present invention. 1 is a commercial frequency power supply, 2 is a power transformer, 3 is a Sirisk rectifier, 4 is a DC positive electrode bus, 5 is a DC negative electrode bus, 6 is a detection element, 81 to 82 are Sirisk switches, 1) 1-I
)2 is a stopper diode.

Claims (1)

[Scope of utility model registration request] A converter that steps down the AC power input from the commercial frequency power supply bus to the required value, a power transformer that is shared with the inverter, converts the input AC power into DC power, supplies the raw power to the load, and regenerates the power. A first stopper is inserted between the DC output side of this rectifier and the DC positive bus to guide the power to the load. a second stopper diode that is inserted into the DC negative electrode bus side and conducts the power to the power supply side;
between each cathode of the stopper diode, and between the first and second stopper diodes.
A sirisk switch is cross-connected between the anodes of the stopper diodes, and has the function of guiding regenerative power to the power supply side and cutting off the regenerative power, and the regenerative current flowing to the DC bus during regeneration. or a control device for detecting the DC voltage between the DC positive electrode bus and the DC negative electrode bus, and forcibly extinguishing the above-mentioned cyrisk switch based on this detection signal. Device.