JPS6031291B2 - Semiconductor circuit breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in semiconductor shield breakers suitable for high voltage and large current applications.

Conventionally, there is a semiconductor circuit breaker configured as shown in FIG. 1 in order to increase the voltage.

This consists of the main circuit current break circuit 2-1 and the commutation circuit 2-2,
It consists of an auxiliary power supply 3, a control circuit 4, a shunt 5 and a load 6. The main circuit current cutout circuit 2-1 has the reactor 2-1-1-1 and the 1st stage block to the Nth stage block connected in series to the power supply 1. Only the tiered blocks are shown. Main thyristors 2-1-1-2, 2-N of the first and Nth stage blocks
-1-2, capacitor 2-1-1-3-resistor 2-
1-1-4 series circuit, capacitor 2-N-1-3, resistor 2-N-1-4 series circuit, and resistor 2-1-1.
-6, 2-N-1-6 are connected in parallel, respectively.
The commutation circuit 2-2 has a parallel circuit of resistors 2-1-2-10 and capacitors 2-1-2-9, and a resistor 2-N-2-10 on the anode side of the rectifier circuit 2-1-2. Parallel circuits of capacitors 2-N-2-9 are connected in series. Further, on the cathode side of the rectifier circuit 2-1-2, an auxiliary thyristor 2-1-2-12, a resistor 2--2-14, and a capacitor 2-1-2
-13 series circuit and resistor 2-1-2-13 parallel circuit, as well as auxiliary thyristor 2-N-2-12 and resistor 2
1N-2-14, a series circuit of capacitors 2-N-2-13, and a parallel circuit of resistors 2-N-2-13 are connected in series, respectively. The rectifier circuit 2-1-2 includes a parallel circuit of resistors 2-1-2-8, capacitors 2-1-2-7, resistors 2-N-2-8, and capacitors 2-N-2-7. The parallel circuits are connected in series and the parallel circuits are connected in parallel. Auxiliary transformer 2-1-2-1 is connected to rectifier circuit 2-1-2.
An auxiliary power source 3 is connected via the auxiliary power source 3. Note 2--2
12 is a resistor, and 2-1-2-16 is a reactor.
In this way, in order to increase the voltage, the main thyristor 2-1-
The number of series connections of 1-2-2 to 2-N-1-2 was increased, and the commutation circuit 2-2 for supplying reverse current to the main circuit was also made to have a correspondingly high voltage to prevent current limiting and disconnection. Is going.

However, in such a circuit, in order to force a reverse current to flow through the main thyristors 2-1-1-2 and 2-N-1-2 when a short circuit current occurs, the main thyristor with the fastest turn-off time, for example Since the full voltage is applied to -1-1-2, the main sirens 2-1-1-2 will be destroyed. The thyristor 2-1-1-1 becomes energized due to the destruction of the main thyristor 2-1-1-2, and then turns off.
-2 also has the same problem repeatedly. In order to prevent this, there would be no problem if all the main thyristors 2-1-1-2 to 2-N-1-2 could be made to have the same turn-off time, but since this is actually impossible, the main It is possible to add a surge absorption circuit to the circuit, but this design requires extremely complex calculations and layout. Furthermore, the commutation circuit that supplies reverse current to the main circuit is also auxiliary thyristor 2-1-2-12~
As the number of 2-N-2-12 in series increases, the auxiliary syringe that fires last, for example, the total voltage of the reverse current supply capacitor 2-N-2-13 is applied to 2-N-2-12. Therefore, there is a risk that the auxiliary thyristor 2-N-2-12 will be destroyed. Preventing this requires appropriate design of the surge absorption circuit, but this also requires extremely complicated calculations and layout. Of course, the method of selecting and using thyristors with the same turn-on and turn-off times as the main thyristors 2-1-1-2 to 2-N-1-2 used in the main circuit is also used, but this also requires a lot of work time. This will lead to an increase in costs. On the other hand, capacitors 2-1-2-9 to 2-N-2-9, 2-1-2-7 to 2-N-2-7 used in the commutation circuit of the reverse current supply source
, 2-1-2-14 to 2-N-2-14 in series and parallel increases, requiring complicated calculations to equalize the shared voltages, and in addition, the circuit configuration shown in Figure 1 requires high voltage Even if it were possible to achieve standardization, standardization would be troublesome because it would be designed and manufactured for each main circuit voltage. Furthermore, in order to make the conventional semiconductor circuit breaker more popular, there is a device constructed as shown in FIG. 2.

This consists of a main circuit current cutout circuit 2-1-1, a commutation circuit 2-2, an auxiliary power source 3, a control circuit 4, a shunt 5, and a load 6. The main circuit current cutout circuit 2-1-1 is the main thyristor 2-1-1-2, 2-N-1-2 (only two are shown in the diagram, but in reality, multiple thyristors are installed. ), series circuit of capacitor 2-1-1-3-resistor 2-1-1-4,
All of the non-linear surge suction elements 2-1-1-5 are connected in parallel, and this is connected to the power source 1 via the reactor 2-1--1. On the other hand, the commutation circuit 2-1 is the rectifier circuit 2
- Parallel circuit of resistor 2-1-2-8 and capacitor 2-1-2-7 connected in parallel to 1-2 and rectifier circuit 2-
A parallel circuit of resistors 2-1-2-10 and capacitors 2-1-2-9 connected in series to 1-2, and a rectifier circuit 2.
Auxiliary thyristor 2-1-1 connected in series with 1-1-2
-2, 2-N-1-2 (Actually there are 1 to N, but in the figure it is 2
), a parallel circuit consisting of a series circuit of resistors 2-1-2-17 and capacitors 2-1-2-18, and further connected in series to this parallel circuit,
-2-11, auxiliary transformer 2-1-2-1, resistor 2-1
-2-2. In the configuration shown in FIG. 2, when a short circuit current occurs, the main thyristor 2-1-1-2
, 2-N-1-2, for example, 2-1-2-2.
Since the entire current flows through the thyristors 2-1-1-2
is destroyed, resulting in a dangerous situation in which the shearing ability is lost. Furthermore, the commutation circuit 2-1 that supplies reverse current has a large number of parallel auxiliary thyristors 2--1-2, 2-N-1-2, and the auxiliary thyristors that fire first, such as 2-N-1-2. Since the total reverse current to the main thyristors 2-N-1-2 is concentrated at , there is a risk of destruction of the auxiliary thyristors. As a method to prevent these drawbacks, there is a method of aligning the turn-on and turn-off times of the thyristors used, but with this method, the turn-on and turn-off times will not be aligned unless you select from a large number of thyristors due to the hassle of selecting them. This will significantly increase costs. Conventionally, in order to achieve high voltage and large current, a circuit such as a combination of FIGS. 1 and 2, that is, a main circuit, has been connected with a large number of thyristors connected in parallel and connected in series.

This has the disadvantage that the full voltage is applied to the block that turns off the fastest among the parallel-connected blocks when a reverse current is supplied, destroying the thyristor. If one thyristor is destroyed, the thyristor of the next block to be turned off will be destroyed. On the other hand, among the same parallel blocks, all the current is concentrated in the thyristor that turns off the latest, and the thyristor is destroyed. When this thyristor breaks down and turns on, all the current concentrates on the thyristor that turns off the last among the parallel-connected blocks that turn off next, causing the thyristor to break down. If this happens repeatedly, you will lose your cutting ability. These problems are inherent in semiconductor current limiters and circuit breakers that forcibly supply reverse current, and unless these drawbacks are eliminated, they will become unreliable and high-cost circuit breakers. Even in commutation circuits, there are disadvantages in that the current concentrates on the thyristor with the fastest turn-off time among the same parallel thyristors, and that the entire voltage is applied to the block with the fastest turn-off time among the parallel blocks, leading to destruction of the thyristor. . This invention was made in view of the various circumstances mentioned above, and an object of the invention is to provide a semiconductor circuit breaker capable of generating high voltage and large current. Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a circuit diagram showing this embodiment, in which the main circuit current break circuit 2 is the main circuit current break circuit first stage flock 2-1.
- Main circuit current and disconnection circuit Nth stage block 2-N.

This main circuit current break circuit first stage block 2-1 is a main circuit current break circuit series first stage parallel first stage block 2-
1-2 to main circuit current line and disconnection circuit series first stage parallel Nth stage blocks 2-1-N. The parallel first stage block 2-1-2 in the series first stage of the shunt circuit is connected to the main thyristors 2-1-2-2 and the capacitors 2-1-2 in parallel.
A series circuit of three resistors 2-1-2-4 is connected, a reactor 2-1-2 is connected in series to this, and a main syringe 2-1-2 is connected to the reactor 2-1-2. -5
-1 and a commutation circuit 2-1-2-5 consisting of reverse current supply circuits 2-1-2-5 and -2 are connected in parallel. Similarly, the breaker circuit is serially connected to the first stage, and the Nth stage block is parallel to the block 2-1-.
N is reactor 2-1-N-1, main thyristor 2-1
-N-2, capacitor 2-1-N-3, resistor 2-1-
Commutation circuit 2-1-N consisting of N-4, reactor 2-1-N-5--, and reverse current supply circuit 2-1-N-5-2.
-5. However, the first broken circuit in series
The intra-stage parallel first-stage block 2-1-2 to the shunt circuit first-stage parallel N-stage block 2-N-2 are connected in parallel, and the reactor 2-1-1-1 and the non-linear surge Absorption element 2
-1-1-4, capacitor 2-1-1-2, resistor 2-
1-1-3 are connected in series and parallel to the surge absorption circuit 2-1-- are connected, and the main circuit current is cut off.The first stage block 2
-1 is configured. Similarly, a main circuit current cutoff circuit N-stage block 2-N is configured, and this and a main circuit current cutoff circuit first stage block 2-1 are connected in series, and furthermore, a power supply 1
It is connected to the. In the figure, 3 is an auxiliary power supply, 4 is a control circuit, and 5 is a shunt. In such a circuit configuration, power is supplied to the load 6 from the main circuit current break circuit first stage block 2-1 of the main circuit current break circuit 2 to the main circuit current break circuit fourth stage block. 2-N main thyristor 2-1
-2-2 to N-N-2, a gate signal is supplied to the control circuit 4 to turn it off. When turning off, the control circuit 4 connects the commutation circuits 2-1-2-5 to 2-N-N.
-5 supplies a gate signal to the auxiliary thyristor (not shown) to turn on the auxiliary thyristor, and the commutating capacitors (
) is discharged, and a reverse current is supplied from the main thyristor 2-1-2-2 to 2-N-N-2.
This is done by turning off the holding current below 1-2-2 to 2-N-N-2. Next, a fault current removal operation when a short circuit current occurs on the load side will be explained.

The fault current is detected by the shunt 5 and a signal is sent to the control circuit 4. From the control circuit 4 to the commutation circuits 2-1-2-5 to 2-
A gate signal is supplied to the auxiliary thyristor in N-N-5, the auxiliary thyristor turns on, and the commutation circuit 2-1-2-
Discharge the charge in the commutating capacitors in 5 to 2-N-N-2, supply reverse current to the main thyristors 2-1-2-2 to 2-N-N-2, and turn them off as the holding current is below, causing a failure. Remove current. The operation of the main circuit current break circuit series first stage parallel first stage block 2-1-2 to the main circuit current break circuit first stage parallel N stage block 2-1-N is as follows. become. That is, power is supplied to the load 6 by supplying gate signals to the main thyristors 2-1-2-2 to 2-N-1-2 to turn them on. Also, when stopping the power supply to the load 6, the control circuit 4 transfers the power to the commutation circuits 2-1-2-5 to 2.
-1-N-5, each auxiliary thyristor (not shown) is supplied with a gate signal to fire, and each commutating capacitor (not shown) is discharged, and the main thyristor 2-1-1-
This is done by supplying a reverse current from 2 to 2-N-1-2 and turning it off so that the holding current of the main thyristors 2-1-1-2 to 2-N-1-2 is lower than that. Further, a fault current when a short circuit current occurs in the load 6 is detected by the shunt 5 and a signal is sent to the control circuit 4. A gate signal is supplied from the control circuit 4 to each auxiliary thyristor (not shown) in the commutation circuits 2-1-2-5 to 2-1-N-5, and each auxiliary thyristor turns on in the evening. -1-2-5 to 2-1-N-5 discharge the electric charge of the commutating capacitors and supply a reverse current to the main thyristors 2-1-2-2 to 2-N-2-2 to maintain the holding current. The fault current is removed by turning off as follows. In addition, when the main circuit current is disconnected from the first stage block 2-1 to the Nth stage block 2-N' surge, the capacitor 2-1-1
-2 to 2-N-1-2 prevents the application of overvoltage to the main thyristor, and if a larger overvoltage is applied, the non-linear surge absorbing element 2-1-11-4 to 2-N-1-
4, it is safe. The embodiment shown in FIG. 3 described above uses a combination of embodiments for high voltage and large current, so that the drawbacks of the conventional system can be eliminated.
Even when high voltages and large currents are required, standardization can be achieved because the main circuit current and disconnection circuits can be arranged in a building block style. High-voltage, large-current test equipment is expensive, but the method of the present invention is extremely economical because it requires equipment that can test main circuit current and disconnection blocks. In the embodiment shown in FIG. 3 described above, the main thyristor is one parallel circuit and one series circuit in that block. However, by selecting the turn-on and turn-off times of the main thyristor, the thyristor 10-1-4 to 10-1
An equivalent thyristor 10 consisting of 1N, 10-N-4 to 10-N-N is constructed, and the main thyristors 2-1-2 in FIG.
-2 to 21 may be used in place of N-N-2.

Even in this case, it is sufficient that the turn-on and turn-off times are the same within the equivalent thyristor 10 and may be different from those of other equivalent thyristors. This is possible because, as described above, a reverse current is supplied to each equivalent thyristor and variations in turn-on time are narrowed. Even when using an equivalent thyristor in this way, it is easier than when using the conventional method. Although each of the embodiments described above is a case of a DC semiconductor circuit breaker, it can also be implemented in an AC semiconductor circuit or circuit breaker.

Alternatively, the current can be detected by a current transformer instead of the shunt 5, and the main thyristor can be connected in a diode bridge or in anti-parallel with a diode. At present, the high speed breaker is 750V/1500V-4000A/800 ships/100 in DC.
From the 00A class to the direct current of nuclear fusion products and disconnectors, up to 5 dishes V-8 skin A is required. On the other hand, the AC interruption is 440V-1 0A/10 ship at the control center and 3. Tsumugi v/6.6kV/11kV/22kV-
Both high voltage and large current up to several thousand A can fully satisfy the requirements over a wide range. In this invention, if separate rectifier circuits are provided, the accumulated carriers will be uneven, but there is no way to adjust the reverse voltage. Furthermore, a non-polar electrolytic capacitor may be used as a surge absorbing capacitor. In addition, various modifications can be made without changing the gist of the invention. According to the invention described above, it is possible to provide a semiconductor circuit breaker capable of generating high voltage and large current.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of a conventional DC high voltage semiconductor shield circuit breaker, Figure 2 is a circuit diagram of a conventional DC high current semiconductor shield circuit breaker, and Figure 3 is a circuit diagram of a conventional DC high current semiconductor shield circuit breaker.
The figure is a circuit diagram showing one embodiment of the semiconductor shield breaker according to the present invention, and FIG. 4 is a diagram for explaining a modification of FIG. 3. 1...Power supply, 2...Main circuit current or disconnection, 3...
- Auxiliary power supply, 4... Control circuit, 5... Detection circuit such as a shunt or current transformer, 6... Load, 10... Equivalent thyristor. Figure 1 Figure 2 Figure 4 Figure 3

Claims (1)

[Claims] 1 Connect a required number of main thyristors in parallel, connect a first series circuit of a resistor-capacitor in parallel to the anode and cathode of each main thyristor, and connect the first series circuit of a resistor-capacitor and the main thyristor in parallel. A first reactor is connected in series to one end of the connection point, and a commutation circuit that discharges a capacitor and supplies a reverse current to the main thyristor is connected in parallel with the first reactor, and the commutation circuit and the resistor are connected in parallel. - A second reactor is connected in series to the other end of the connection point of the first series circuit of capacitors to form a small block, and a second series circuit of resistor-capacitor and a surge absorption element are connected in parallel to each small block. A plurality of these large blocks are connected in series according to the main circuit voltage, and when a fault current occurs or the thyristor is turned off, the capacitor of the commutation circuit is discharged as a reverse current to the main thyristor, thereby shutting down the main circuit. A semiconductor circuit breaker characterized by its ability to disconnect.