JPS58126225A - D.c. feed circuit - Google Patents

Abstract

PURPOSE:To reduce the cost of a feeding circuit and to reduce the size of the device, by providing a pair of semiconductor breakers common to each of plural sets of feeding circuits and sharing a commutation circuit of said breaker with a semiconductor switches in each feeding circuit. CONSTITUTION:Plural sets of feeder circuits 1a, 1b are comprised of a semiconductor switch 15, diode 16, thyristor 17, D.C. current transformer 18 and a current detector 19, and the power is fed through a thyristor rectifier 5, and a common power source circuit 4. Here the anode side of said switch is connected to said circuit 4 while the cathode side is connected to the load circuit, while furthermore the anode side of the diode 16 and the cathode side of the thyristor 17 are connected to the cathode side of said switch 15. Then the current in said circuits 1a, 1b is detected by the D.C. current transformer 18, and in accordance with the detected result, said switch 15, semiconductor breaker 3 and a rectifier 5 are controlled through the current detection circuit 19.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor type DC power supply circuit that includes a plurality of sets of DC power supply circuits each having a semiconductor switchgear.

DC switchgears using semiconductors include those that have a commutation circuit and can cut off the current (hereinafter referred to as semiconductor circuit breakers), and those that do not have a commutation circuit and generate a gate signal when the thyristor current becomes zero. There are devices that turn off the thyristor and put it in a blocking state (hereinafter referred to as semiconductor switches); I can only let it flow. For this reason, for example, when absorbing regenerative braking power from vehicles at a DC substation for electric railways, or when performing extended power supply, semiconductor breakers must be connected in antiparallel. Figure 1 shows the conventional semiconductor DC circuit breaker. The power feeding circuit (la)t(lb) is a plurality of sets of DC feeding circuits, each including a semiconductor breaker (2) and a semiconductor breaker (3) connected in parallel in the opposite direction to these circuits. It is connected to a common power supply circuit (4). (The phrase is a semiconductor rectifier that supplies DC power to a load (not shown) via the feeding circuit (ia) m (ib). (7) is a current detection circuit configured to send a cutoff signal to the semiconductor breaker (2) * (33). In the basic configuration of the device, (8) is the king thyristor that carries the load current;
(9) is a commutating thyristor, (2) is a commutating capacitor, (
b) is a commutation reactor, and (2) is a preliminary charging circuit.

Next, the operation of the conventional example shown in FIG. 1 will be explained.

When an overcurrent occurs in the direction from the rectifier (5) to the feeder circuit (la), the current detection circuit (7) operates and sends a cutoff signal to the semiconductor breaker (2), causing the feeder circuit (la
) stops supplying power to the load circuit. On the other hand, power supply circuit (4)
If an accident occurs in a load circuit connected to Rurui or other Ki IIc circuits (tb) or (xc), the current from the vehicle in the neighboring substation or load circuit will be transferred to the feeding circuit (
The overcurrent flows back through the semiconductor breaker (3) of ta). Therefore, the current detection circuit (7) operates and sends a cutoff signal to the semiconductor breaker (3). If there is an extended power supply from an adjacent substation or a vehicle has regenerative braking, each feeding circuit needs to flow DC current in both directions.
In each feeding circuit, semiconductors wTJa were connected in antiparallel to perform the protection operation as described above.

In addition, during normal operation, when there is a power outage in the feeding circuit, a cutoff signal is sent to either the semiconductor breaker (2) or (31) which is in the energized state.

Power to the feeding circuit was stopped.

Conventional DC power supply circuits are configured as described above, so two sets of semiconductor circuit breakers are required for each power supply circuit, and in cases where there are many electrical circuits, such as in railway DC substations, a commutation circuit is required. As the number of semiconductor circuit breakers increases, the cost of equipment becomes prohibitive, and the size of the equipment also increases.The present invention was made to eliminate the drawbacks of the conventional circuit breakers as described above, and The electric circuit is a semiconductor switch,
For reverse current, make it common through a diode,
Connected to a common power supply circuit through a set of semiconductor circuit breakers,
Furthermore, by connecting the commutation circuit of the semiconductor breaker and each feeding circuit through a thyristor switch, the commutation circuit of the semiconductor breaker can be shared with the semiconductor switch, and the semiconductor breaker can be integrated as a whole. It is better to consist of one set,
This enables a small, low-cost DC power supply circuit.

An embodiment of the present invention will be described below with reference to the drawings. Third
In the figure, (ta) and (xb) indicate multiple sets of power supply circuits, each of which is a semiconductor switch.

It has a diode, a thyristor, a DC current transformer Q, and a current detection circuit. (The DC output anode a of the rectifier is connected to the common power supply circuit (4). The anode side of the half-stop switch is connected to the common 11E#1 circuit.

The cathode side is connected to the load circuit, the anode side of the diode ring and the cathode side of the thyristor.

It is connected to the cathode side of the semi-integrated switch +151. The DC current transformer detects the current of the feeding circuit (la), and the current detection circuit determines that the semiconductor switch (151,
A signal is sent to a semiconductor breaker (3) and a thyristor rectifier (5). The other feeding circuit (lb) is configured in the same manner as the feeding circuit (la). (The same applies to multiple sets of feeding circuits not shown) Next, each feeding circuit (1aL
The cathode sides of diode 4 (lb) are connected in common at point (2), and the anode sides of the thyristors are connected in common at point (14).The semiconductor breaker (3) is connected in common at point (14).

The anode side of the star (8) is connected to the point (2), and the cathode side is connected to the common power supply circuit (4). Furthermore, the point part is connected to the commutation circuit of the semiconductor breaker (3) so that the commutating thyristor (9) is connected between the point part and the point part.

Next, the present invention will be explained in detail with reference to the embodiment shown in FIG.
In normal operation, for example, when supplying current from the feeding circuit (la) to a load (not shown), a rectifier (5
) - Common power supply circuit (4) - Semiconductor switch ll@ - Feeding circuit (la) - Meridian of load (not shown), adjacent substation or regenerative vehicle (not shown) - Kigame circuit (1
The diode of b) - the main thyristor (8) in the semiconductor breaker (3) - the common power supply circuit (4) - the semiconductor switch (
Direct current is supplied through a path of I@-feeding circuit (la)--a load (not shown).

Next, when cutting off the DC current to the feeding circuit (la), the semiconductor switch -0 gate signal of the feeding circuit (la) is stopped and the semiconductor breaker (3) is cut off.

The main thyristor (8) is used to cut off the semiconductor breaker (3).
In addition to stopping the gate signal of the commutation, risk (9
) 1, the electric charge of the commutating capacitor Q[), which had been previously charged to the polarity shown in the figure by the pre-charging circuit (2), is transferred to the commutating reactor (b), the main thyristor (8), Commutation thyristor (9), commutation capacitor 0
p1 is carried out by commutating tRlR, which was discharged through the path of 0 and flowing to the main thyristor (8), to the commutating circuit.

On the other hand, at this point, the semiconductor switch O@ has stopped sending the gate signal, but the current circuit Ii (5) and the electric circuit (la
) continues to flow. When the semiconductor breaker (3) completes breaking, the commutating capacitor is charged to the opposite polarity as shown. At this time, when the thyristor (b) is turned on,
The electric charge of the commutating capacitor U is transferred to the thyristor aη, the semi-integrated switch 05), the commutating reactor (B), and the commutating capacitor (
It is possible to commutate the load current that flows through the semiconductor switch (16) through the path 10 and to cut off the thyristor switch Hiroshi in exactly the same way as the semiconductor breaker (3). At this time, the power supply from the rectifier (5) to other power supply circuits (lb) is not affected in any way.

The above operation is performed in exactly the same way when stopping other feeding circuits and a plurality of sets of feeding circuits.

However, the thyristor αη of each feeding circuit only needs to supply the commutated current of the semiconductor switch (II) as described above.
Since no load current flows, like the commutating thyristor (9) of the semiconductor breaker (3), no cooling device is required.
It is small in size.

As described above, according to the present invention, one set of semiconductor circuit breakers is provided in common to each of the plurality of sets of cage circuits, and each of the cage circuits is composed of a semiconductor switch, a diode, and a thyristor, and one set of The commutation circuit of the semiconductor breaker can be shared as a commutation circuit for the semiconductor switch of each feeder circuit, and compared to the case where a semiconductor breaker is provided in each feeder circuit, the circuit cost is reduced, and The device is made smaller.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional device, FIG. 2 is a circuit connection diagram showing the configuration of a semiconductor breaker, and FIG. 3 is a circuit connection diagram showing an embodiment of the present invention. Note that the same reference numerals in the figures indicate the same or similar parts. la, lb... DC feeding circuit %2.3... Semiconductor breaker, 5... Rectifier, 6.18... DC transformer, 7, 19... Current acclimatization circuit, 8... King thyristor, 9... Commutation thyristor, 10°... Commutation capacitor, 11... Commutation reactor, ]2... Pre-charging circuit, ]5... Semiconductor switch, ]6...Diode, 17...Thyristor. Agent Makoto Kuzuno- 111

Claims (1)

[Claims] It has a DC power supply circuit that is supplied with power from a rectifier, and a plurality of sets of feeder circuits made of semiconductor switches are connected to the #EMDC power supply circuit, and the outputs of the plurality of sets of feeder circuits are connected through diodes. The nine points connected in common through a 1ItI diode and the DC power supply circuit are connected through a semiconductor breaker, and the commutation circuit of the semiconductor breaker and the plurality of sets of A DC power supply circuit characterized in that the output sides of the feeder circuits are connected via thyristors.