JPH02184220A - Multi-terminal dc circuit breaker - Google Patents

Abstract

PURPOSE:To reduce the overall size by arranging diodes for performing three rolls of matching, counter-flow blocking and transistor protection at respective input sides and sharing the inputs at the cathode side thereby performing interruption through a single large-capacity transistor. CONSTITUTION:Currents are fed normally from both terminals (a), (b) to respective diodes 2 and combined at the cathode side of the diodes 2. The resultant current is fed through a transistor 1 and a current sensor 5. Upon occurrence of a short circuit in a system connected with a DC circuit breaker, the current sensor 5 detects overcurrent while a voltage sensor 6 detects undervoltage, then a control section 4 interrupts the base current of the transistor 1 through a base drive circuit 3 so that the transistor 1 is turned OFF to interrupt fault current.

Description

[Detailed Description of the Invention] [Industrial Application Field] The invention of B relates to a DC breaker used for protection of a DC power system.

[Conventional technology]

Cutting off direct current is difficult because of the method of processing the magnetic energy stored in the line inductance and the method of forcibly narrowing down the current to create four points of current zero. Conventionally, mechanical circuit breakers were mainly used, but in recent years With the advancement of power semiconductors, DC circuit breakers using semiconductor elements have come into use.

FIG. 5 is a diagram showing a configuration diagram of a conventional DC breaker. In the figure, (1) is a DC cutoff transistor element, (2
) is a diode for reverse current blocking and transistor protection, (3)
is the base drive circuit of the transistor element, (4) is the control section, (5) is the output current sensor, (6) is the input voltage sensor, and (7) is the connection between the input voltage sensor (6) and the control section (4). A signal line (8) is a signal line connecting the output current sensor (5) and the control unit (4), and (9) is a conventional circuit breaker.

Next, the operation will be explained using FIG. 5.

A normal current flows from the transistor element (1) through the diode (2) and the sensor (5). In addition, the voltage sensor (6) and current sensor (5) send normal value signals to the control unit (4) through signal lines (7) and (81), respectively.
). On the other hand, the base drive circuit (3) receives a normal signal from the control section (4) and applies an appropriate base current to the transistor (1), so that the transistor is in a conductive state. When a DC circuit breaker is connected and a short-circuit accident occurs in the t-system, the current sensor (5) detects an overcurrent, and the input voltage sensor (6) detects an undervoltage and sends an abnormal signal to the signal lines (7), (It is sent to the control unit (4) through 81. The base drive circuit (3) receives the abnormal signal from the control unit (4), stops the base current of the transistor (1), and turns off the transistor (1). , interrupts the fault current.The above is an explanation of the operation of a DC breaker as a standalone unit, but when the DC breaker is actually connected to a DC system and used, the DC circuit breaker interrupts the fault current as shown in Figure 6 (a). In many cases, the output side of the circuit is shared.This is to take advantage of direct current and match the two systems with diodes to improve reliability and to effectively accommodate power.As shown in Figure 6 (a). (1) to (9) are the same as in Figure 5, but (
10a) is the DC/DC converter of system A, (1ob
) is the system B DC/DC converter. Electric power passes through each circuit breaker from the DC/DC converters of system A and system B, is matched at point 0, and reaches load 01). Normally, DC/DC converters or other systems are operated under constant voltage control, so when two or more converters or systems are matched, a series diode is required for each converter or system to avoid interference between the converters or systems. Become. In FIG. 6(a), the diode (2) also serves this role.

What is the operation of the DC breaker (9) in normal and abnormal conditions?

This is the same as explained in FIG.

Further, as another application example of the DC circuit breaker, as shown in FIG. 6(b), the input side of the DC circuit breaker is often shared and used for branching each load. This way, when one load fails, only that load can be removed and the system can be used continuously.

This is to improve reliability and to suppress overcurrent that flows when a load fails to minimize failures. In Figure 4(b), (1) to (9) are the same as in Figure 5, but
QOl is the DC/DC converter of the system, Ol) is the system A
, ■ is the load on system B. Electric power is separated into both systems A and B at the 0 point from II, passes through each circuit breaker, and reaches the load θ1) and the loads a and b. The transistor protection diode (2) has the role of preventing reverse voltage from being applied to the transistor (1) and destroying it when a ground fault occurs at the zero point.

What is the operation of the DC breaker (9) in normal and abnormal conditions?

This is the same as explained in FIG.

[Problem to be solved by the invention]

Conventional DC circuit breakers were configured as described above.
When used in an actual system, one circuit breaker is required for each system, which increases the weight and volume of the system, which may pose a problem in terms of implementation. For starvation aircraft, space 8
! In the dexterous power system, especially t! Due to the demand for smaller and smaller power supply systems, there are no system branches, and it may be necessary to construct systems that do not have power flexibility.

Party B's invention was made to solve the problems mentioned above, and is a compact device for connecting multiple systems.

The purpose is to obtain a lightweight DC breaker.

Another object of the present invention is to obtain a small and lightweight DC breaker for distributing power from one system to a plurality of loads.

[Means to solve the problem]

The DC breaker according to the present invention connects a diode to each input side and has three roles: matching, blocking reverse current, and protecting the transistor.

It has a configuration in which each input is shared on the diode cathode side, and one large transistor is used for breaking, and multiple circuit breakers are combined into one, making it compact and lightweight.

Further, in a DC breaker according to another aspect of the present invention, the input terminals are combined into one, and one input voltage sensor and a plurality of transistors for each load are connected to the input side in common, and each transistor is connected to the opposite side. It has a configuration in which voltage protection diodes are connected in antiparallel to combine multiple circuit breakers into one, making it smaller and lighter.

[For production]

The transistor according to the present invention has the ability to cut off the combined current of a plurality of systems, and is turned off or conductive depending on the voltage and output current values of each system or by an external signal.

Further, the transistors according to another aspect of the present invention each have the ability to cut off the maximum fault current of the system, and the plurality of transistors can be independently cut off depending on the power of the grid and the value of each output current, or by an external signal. Or it becomes a conductive state.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A DC breaker according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a DC circuit breaker according to an embodiment of the present invention, and in FIG. 2, (1) is a transistor element for DC interruption, (2) is a diode for reverse current blocking and transistor protection, and (3) is a transistor element. element pace drive circuit,
(4) is a control unit, and (5) is an output current sensor.

(6) is the input voltage sensor, (7) is the input voltage sensor (6
) and the control section (4), (8) is a signal line that connects the output current sensor (5) and the control section (4), and ■ indicates a DC breaker according to the present invention.

next,! l! II work will be explained using FIG.

Under normal conditions, the fl current is input from both terminals a and b, passes through each diode (2), joins at the anode side of the diode (2), and then flows through the transistor (1) and current sensor (5). In addition, each voltage sensor (6) of a and b,
The current sensor (5) sends each normal value signal to a signal i (71
, (81) to the control unit (4). On the other hand, the base drive circuit # (3) receives the normal signal from the control unit (4) and sends the base current according to the main circuit current to the transistor (1). In this case, it is simply necessary to use a transistor with a current rating twice that of the conventional example shown in FIG.

Therefore, the base current is also required to be approximately twice as large. When a short circuit occurs in a system to which a DC breaker is connected, the current sensor (5)
detects overcurrent, and each voltage sensor (
6) detects the undervoltage and sends the abnormal signal to each signal line (7).
, [Sent to the control unit (4) through 81. The pace drive circuit (3) receives the abnormality signal from the control unit (4), stops the base current of the transistor (1), turns the transistor (1) off, and cuts off the fault current. The operation of the DC breaker according to the present invention has been described above, and FIG. 2 shows an example in which it is actually applied to a power system. In Figure 2,
(10m) (10b) is a DC/DCC/type-ta, OD is a load, and ■ is a DC breaker according to the present invention.

The two DC/DCC/type controllers (10a) and (10b) are each controlled at a constant voltage and operated in parallel. Diode (2) is DC/DCC/formula-ta (10a) (10b)
It also serves as a means to avoid interference. Figure 6(a)
Compared to the conventional example, it performs the same function as a circuit breaker, but the transistor (1) and base drive circuit (3)
), a control section (4), and a current sensor (5), which were conventionally two, are now integrated into one, making it easier to use. In this usage example, an example of two input terminals has been described, but it goes without saying that the number of input terminals may be any number as long as it is two or more.

FIG. 3 is a block diagram of a DC breaker according to another embodiment of the present invention, and in FIG. 2, (Im) and (lb) are transistor elements for DC interruption, (2a) and (2b)
is a transistor protection diode, (3m), (
3b) is the base drive circuit of the transistor element, (
4a) and (4b) are control units.

(5m), (5b) is the output current sensor, and (6) is the input voltage sensor.

(7m) and (7b) are signal lines connecting the input voltage sensor (6) and the control unit (4a) and (4b); (8a)
), (8b) are output current sensors (5a), (5
b) and a signal line connecting the controllers (4a) and (4b).

(■ indicates a DC breaker according to the present invention.

Next, the operation will be explained using FIG. 3.

Under normal conditions, current is input from the i terminal, passes through the voltage sensor (6), branches at the 0 point, and flows through the transistor (
la), (lb) l output current sensor (5a),
(5b). In addition, the system input voltage sensor (6) and each current sensor (5a5.
b), normal value signals are connected to signal lines (7a) and (7b), respectively.
), (8a), (8b) through the control unit (4a
), (4b). On the other hand, the base drive circuits (3a), (3b) control the control units (4a), (
In response to the normal signal from 4b), a pace current of t is applied to the transistors (la) and (Ib) according to each load current, and the transistors are in a conductive state. If a short circuit occurs in the load connected to terminal a, the current sensor (5
a) detects overcurrent and voltage sensor (6) detects undervoltage.

Abnormal signals are sent to the control unit (4a) through signal lines (8a) and (7a), respectively. The base drive circuit (3a) is
The transistor (
1&), the transistor (1a) is turned off to cut off the fault current. On the other hand, an abnormal signal is sent from the signal line (7b) to the control unit (4b) on the b terminal side, but the signal sent from the output current sensor (5b) through the signal line (8b) is a normal signal, so control is performed. Part (4b)
does not issue a trip signal to the base drive circuit (3b), so the transistor (1b) remains conductive. Conversely, if a short-circuit accident occurs in the load connected to the terminal, the transistor (1b) is turned off, the accident is removed, and the transistor (1a) remains conductive. The operation of the DC breaker according to the present invention has been described above, and FIG. 4 shows an example in which it is actually applied to a power system. In Fig. 4.

0 [is the DC/DC converter, OD, (to) is the load, C
3) is a DC breaker according to the present invention. 2 load 0
1), (E are respectively connected to output terminals a and b of the cutoff Wl■ according to the present invention and operated.Diode (2a)
, (2b) means that even if the input terminal i, the input line, or the branch point O should have a ground fault, the transistor (Ia),
It plays a role in preventing damage due to reverse voltage being applied to (Ib).

Compared to the conventional example shown in Figure 6(b), it performs the same function as a disconnector, but the conventional example has no diodes inserted in series, and the conventional example has two voltage sensors (6). are combined into one and made easy. In particular, the efficiency of the DC circuit breaker can be improved by eliminating the series diode. In this usage example.

Although the explanation has been given using an example of two output terminals, it goes without saying that the number of output terminals may be any number as long as it is two or more.

〔Effect of the invention〕

As described above, according to the present invention, the DC circuit breaker has multiple terminals, the number of components of the T-copter circuit breaker that is shared in common on the anode side of the diode is reduced, and it is possible to make the circuit breaker smaller and lighter. This also has the effect of improving reliability.

According to another invention of the present invention, the DC breaker has multiple terminals and is shared on the input side of the transistor, which reduces the number of components of the breaker, making it possible to make it smaller and lighter. Reliability is improved, and since the series diode is removed, a highly efficient DC breaker with low loss can be constructed.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a DC breaker according to an embodiment of the present invention, Fig. 2 is a diagram showing an application example of the DC breaker according to the invention, and Fig. 3 is a diagram showing a DC breaker according to another embodiment of the invention. FIG. 4 is a diagram showing another application example of the DC breaker according to the present invention, FIG. 5 is a configuration diagram of a conventional DC breaker, and FIGS. 6(a) and 6(b) are diagrams showing a conventional DC breaker. It is a figure showing an example of application of a container. In the figure, (1) is a transistor element, (2) is a dinate, (3) is a drive circuit, (4) is a control unit, and (5) is a drive circuit.
) is the output current sensor, (6) is the input voltage sensor, and ■ is the DC breaker. Note that the same or corresponding parts in the two figures are designated by the same reference numerals.

Claims (2)

[Claims] (1) diodes for backflow blocking and transistor protection, each connected to a plurality of input terminals and whose output sides are connected to each other via a connection line; an input voltage sensor provided on the input side of each of the plurality of diodes; a transistor element for DC cutoff whose input side is connected to the connection line; an output current sensor connected to the output side of the transistor; a drive circuit that drives the transistor element;
A multi-terminal DC breaker comprising: a control section that controls the drive circuit based on the outputs of the input voltage sensor and the output current sensor. (2) An input voltage sensor connected to one input terminal, a plurality of transistor elements for each load connected in common to this input voltage sensor on the input side, and connected in antiparallel to each of the transistor elements. A reverse voltage protection diode, an output current sensor connected between the transistor element and the output terminal of a DC breaker corresponding to the transistor element, a drive circuit that drives each of the transistor elements, the input voltage sensor and the output. A multi-terminal DC breaker comprising: a control section that controls each of the drive circuits based on the output of the current sensor.