WO2017221561A1

WO2017221561A1 - Direct current circuit, moving body and power supply system

Info

Publication number: WO2017221561A1
Application number: PCT/JP2017/017392
Authority: WO
Inventors: 直森田
Original assignee: ソニー株式会社
Priority date: 2016-06-20
Filing date: 2017-05-08
Publication date: 2017-12-28
Also published as: JP6977721B2; JPWO2017221561A1

Abstract

[Problem] To provide a direct current circuit capable of, when a semiconductor is used for suppressing an arc discharge, securing safety even if a short circuit occurs when the semiconductor has deteriorated. [Solution] Provided is the direct current circuit comprising: a first current path and a second current path provided in parallel on a path where a direct current flows; a circuit using a first switch provided on the first current path to allow a pulsed current of a predetermined duration to flow when the direct current in the second current path is shut-off; and a second switch provided at a stage preceding the first switch, and of which the connection is maintained by a pulling force from a fuse. When the fuse melts, the second switch adopts an open state. The fuse has such a rating as not to melt at a rated energization current during rated energization of the circuit.

Description

DC circuit, moving body and power supply system

The present disclosure relates to a DC circuit, a moving body, and a power supply system.

アーク Arc discharge occurs when power is cut off in both DC and AC power supplies. In the case of AC, since there is a moment when the voltage becomes zero every predetermined time (for example, every 10 milliseconds), arc discharge naturally stops at least within the predetermined time (for example, within 10 milliseconds). However, with DC power supply, arc discharge does not stop naturally because there is no moment of zero voltage.

For this reason, techniques for suppressing the occurrence of arc discharge when power is cut off in the case of direct current power supply have been disclosed (see

Patent Documents

1 and 2, etc.).

JP 2003-203721 A Special Table 2014-520208 Publication

In the case of DC power supply, it is of course possible to suppress the occurrence of arc discharge when power is cut off, but it is not preferable that the construction for suppressing the occurrence of arc discharge becomes large, and the occurrence of arc discharge is suppressed. It is also not preferable to reduce the power supply efficiency during the DC power supply by adding the configuration for this. Therefore, it is desirable to suppress the occurrence of arc discharge with a small-scale configuration when cutting off DC power without reducing power efficiency when supplying DC power.

Therefore, in the present disclosure, the generation of arc discharge is suppressed with a small-scale configuration when the DC power is cut off without reducing the power efficiency when supplying DC power, and the semiconductor switch is used when the semiconductor switch is used to suppress arc discharge. A new and improved DC circuit, moving body and power supply system capable of ensuring safety even when a short circuit occurs due to deterioration of a switch are proposed.

According to the present disclosure, the first current path and the second current path provided in parallel in the path through which direct current flows and the first switch provided on the first current path are used to generate the second current. A circuit for supplying a pulsed current for a predetermined period when a direct current in the path is interrupted, a fuse provided in front of the first switch, and a resistor provided between the fuse and the circuit. Is provided with a DC circuit having a rating that does not melt at the temperature of the resistor due to the flow of a rated current during the rated current application time of the circuit.

According to the present disclosure, a first current path and a second current path provided in parallel in a path through which direct current flows, a first current fuse provided on the first current path, and the first current path On the current path, at least two thermal fuses provided in parallel with the first current fuse, and two diodes provided alternately in parallel downstream of the first current fuse and the at least two thermal fuses; A resistor provided between the two thermal fuses and a circuit for passing a pulsed current for a predetermined period when a direct current is interrupted in the second current path; and a second current fuse provided in parallel with the resistor And the second current fuse has a rating that does not blow at the temperature of the resistor due to the flow of a rated energization current during the rated energization time of the circuit. DC circuit is provided.

According to the present disclosure, the first current path and the second current path provided in parallel in a path through which direct current flows and the second switch using the first switch provided on the first current path. A circuit for supplying a pulsed current for a predetermined period when a direct current in the current path is interrupted, and a second switch provided in front of the first switch and maintained in connection by a tension of the fuse, wherein the fuse When blown, the second switch is opened, and a DC circuit is provided in which the fuse has a rating that does not blow at the rated energization current during the rated energization time of the circuit.

Moreover, according to the present disclosure, a moving object including the DC circuit is provided.

According to the present disclosure, at least one of the DC circuits provided between the battery that supplies DC power, a drive unit that is driven by the DC power supplied from the battery, and the battery and the drive unit. A power supply system is provided.

As described above, according to the present disclosure, generation of arc discharge is suppressed with a small-scale configuration when DC power is cut without reducing power efficiency when supplying DC power, and a semiconductor is used to suppress arc discharge. Thus, it is possible to provide a new and improved DC circuit, moving body, and power supply system that can ensure safety even if a short circuit occurs due to deterioration of the semiconductor.

Note that the above effects are not necessarily limited, and any of the effects shown in the present specification, or other effects that can be grasped from the present specification, together with or in place of the above effects. May be played.

It is explanatory drawing which shows the structural example of the DC circuit which concerns on one Embodiment of this indication. It is explanatory drawing which shows the DC circuit 100 of the state by which the fuse F1 was blown out. It is explanatory drawing which shows the time change of the electric current which flows into the fuse F1 with a graph. It is explanatory drawing which shows the state of switch FS1 and fuse F1 at the time of normal. It is explanatory drawing which shows the state of switch FS1 and fuse F1 when fuse F1 blows. It is explanatory drawing which shows the state of switch FS1 and fuse F1 at the time of normal. It is explanatory drawing which shows the state of switch FS1 and fuse F1 when fuse F1 blows. It is explanatory drawing which shows the state of switch FS1, switch FS1, and fuse F1, F2 at the time of normal. It is explanatory drawing which shows the state of switch FS1 and fuse F1, F2 when fuse F1, F2 fuses. It is explanatory drawing which shows the state of switch FS1, fuse F1, and capacitor C11 at the time of normal. It is explanatory drawing which shows the time change of the electric current which flows into the fuse F1 and the capacitor C11 with a graph. It is explanatory drawing which shows another structural example of the DC circuit which concerns on one Embodiment of this indication. It is explanatory drawing which shows the time change of the electric current which flows into the fuse F1 of the DC circuit 100 shown in FIG. 12 with a graph. It is explanatory drawing which shows the example of a connection of switch FS1 and fuse F1, F2. It is explanatory drawing which shows the example of a connection of switch FS1 and fuse F1, F2. It is explanatory drawing which shows another structural example of the DC circuit which concerns on one Embodiment of this indication. It is explanatory drawing which shows another structural example of the DC circuit which concerns on one Embodiment of this indication. It is explanatory drawing which shows another structural example of the DC circuit which concerns on one Embodiment of this indication. 5 is an explanatory diagram illustrating an operation of a DC circuit according to an embodiment of the present disclosure. FIG. 3 is an explanatory diagram illustrating an example of a functional configuration of a moving body 40 including a DC circuit 100. FIG.

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<1. One Embodiment of the Present Disclosure>
[1.1. background]
Before describing an embodiment of the present disclosure in detail, first, the background of the embodiment of the present disclosure will be described.

In both DC power supply and AC power supply, when the power is cut off, if the voltage and current exceed a certain value, a spark or arc discharge occurs due to the potential difference between the electrodes. In the case of AC, since there is a moment when the voltage becomes zero every predetermined time (for example, every 10 milliseconds), arc discharge naturally stops at least within the predetermined time (for example, within 10 milliseconds).

However, in the case of DC power supply, unlike AC power supply, there is no moment when the voltage becomes zero, so arc discharge does not stop naturally. Arc discharge may cause contact deterioration such as fusing and welding of metal, which may reduce the reliability of power supply.

For this reason, a technique aimed at suppressing the occurrence of arc discharge when the power is cut off in the case of direct current power supply is disclosed. For example, a technique for avoiding by connecting a snubber circuit using a capacitor and a resistor between swinging contacts has been proposed.

However, in order to prevent arc discharge using a snubber circuit in the case of direct current power supply, a sufficient effect cannot be obtained unless a capacitor with a large capacity and a small resistance are used. It will become. Further, when arc discharge is prevented by using a snubber circuit, if an attempt is made to reconnect to a DC power supply after the DC power is cut off, a short current due to a charge charged in a capacitor having a large capacity increases and the contact is welded.

In addition, when DC power is supplied by inserting / removing the plug into / from the plug receptacle, a mechanical switch is provided on the plug to prevent arc discharge, and the mechanical plug is removed when the plug is removed from the plug receptacle. There is also a technique for preventing arc discharge by operating a switch. However, in this technique, it is necessary to force the user to perform a complicated operation of operating a mechanical switch when the plug is removed.

There is also a method of mechanically removing arc discharge. However, in order to remove arc discharge mechanically, it is necessary to increase the contact peeling speed or to peel off the arc with a magnetic circuit, which increases the size of the circuit for removing arc discharge. End up.

In the case of direct current power supply, there are

other Patent Documents

1 and 2 as other techniques for suppressing the occurrence of arc discharge when power is cut off.

Patent Document 1 discloses a technique for suppressing the occurrence of arc discharge by providing a switching element on a path through which a current flows during DC power supply and turning off the switching element when the plug is removed from the plug receptacle. Yes.

However, in the technique disclosed in Patent Document 1, since current flows through the switching element during DC power supply, power is consumed in the switching element during DC power supply, and the switching element generates heat during DC power supply.

The above Patent Document 2 also suppresses the occurrence of arc discharge by providing an arc absorption circuit including a switching element on a path through which a current flows during DC power supply, and turning off the switching element when the plug is removed from the plug receptacle. The technology is disclosed.

However, in the technique disclosed in Patent Document 2, two switching elements as an arc absorption circuit and a timer for turning off the switching elements are provided, arc power is temporarily stored, and the stored power A circuit for discharging the battery becomes necessary, and the circuit becomes larger.

Therefore, in view of the above-described background, the present disclosure has intensively studied a technology that can suppress the occurrence of arc discharge with a small-scale configuration when cutting off DC power without reducing the power efficiency when supplying DC power. went. As a result, as described below, the present disclosure provides two contacts on the positive electrode, and suppresses the voltage generated between the electrodes when the DC power is cut off when switching the contact with the power receiving electrode. Thus, the inventors have devised a technique that can suppress the occurrence of arc discharge with a small-scale configuration when the DC power is cut without reducing the power efficiency when supplying DC power.

Furthermore, the present disclosure has intensively studied a technology capable of ensuring safety even when a short circuit occurs due to deterioration of the semiconductor switch when the semiconductor switch is used for suppressing arc discharge. As a result, as described below, the present disclosure has devised a technique that can ensure safety even when a short circuit occurs due to deterioration of the semiconductor switch when the semiconductor switch is used to suppress arc discharge. It was.

The background of the embodiment of the present disclosure has been described above. Subsequently, an embodiment of the present disclosure will be described in detail.

[1.2. Configuration example]
FIG. 1 is an explanatory diagram illustrating a configuration example of a DC circuit according to an embodiment of the present disclosure. FIG. 1 shows a configuration example of a DC circuit for the purpose of suppressing arc discharge when the DC power supplied from the DC power supply is cut off. Hereinafter, a configuration example of a DC circuit according to an embodiment of the present disclosure will be described with reference to FIG.

The DC circuit 100 shown in FIG. 1 is provided on a path through which DC power is supplied from a DC power supply (not shown) to the load 10. The DC power supply outputs DC power having a predetermined voltage Vs. The DC circuit 100 shown in FIG. 1 is provided between the positive electrode side of the DC power source and the load 10. The DC circuit 100 has a configuration that suppresses the occurrence of arc discharge when a DC current from a DC power supply is interrupted.

The DC circuit 100 includes a MOSFET T1, a capacitor C1, a resistor R1, a diode D1, a switch SW1, and a switch circuit 110. The switch circuit 110 includes a switch FS1 and a fuse F1. The DC circuit 100 allows a current to flow through the main system and the sub system that are parallel in the path through which the DC flows. A system in which the switch SW1 is provided is a main system, and a system in which the MOSFET T1 is provided is a sub system. The MOSFET T1, the capacitor C1, the resistor R1, and the diode D1 function as a voltage integrating circuit.

The MOSFET T1 uses an n-type MOSFET (Metal Oxide Semiconductor Field Effect Transistor) in the present embodiment. The capacitor C1 is provided between the drain terminal and the gate terminal of the MOSFET T1. The resistor R1 is provided between the gate terminal and the source terminal of the MOSFET T1. The capacitor C1 and the resistor R1 are connected in series. The circuit composed of the MOSFET T1, the capacitor C1, the resistor R1, and the diode D1 is a circuit provided for suppressing a current flowing from the DC power source to the load 10 when the switch SW1 is switched from the on state to the off state.

The operation of the DC circuit 100 will be described. When the switch SW1 is in the off state, the MOSFET T1 is also in the off state, so that no current flows from the DC power source to the load 10. Thereafter, when the switch SW1 is operated and the state of the switch SW1 shifts to the ON state, a current flows from the DC power source to the load 10, but in this state, the MOSFET T1 is continuously in the OFF state, and the current is not supplied to the MOSFET T1. Does not flow.

After that, when the switch SW1 is operated and the switch SW1 is turned off, no current flows from the DC power source to the load 10. At this time, the voltage at both ends of the switch SW1 generated when the switch SW1 is turned off (by disconnecting both ends of the switch SW1) induces the gate voltage of the MOSFET T1 through the capacitor C1, and the MOSFET Turn T1 on. When the MOSFET T1 is turned on, a current flows in the direction of decreasing the voltage across the switch SW1 from the DC power source toward the load 10.

The MOSFET T1 is turned on, and a current flows in a direction to decrease the voltage across the switch SW1 from the DC power source toward the load 10, whereby the voltage across the switch SW1 is reduced. By reducing the voltage across the switch SW1, the switch SW1 does not cause arc discharge even when the switch SW1 is turned off.

The voltage between the drain terminal and the source terminal of MOSFET T1 falls within the voltage along the transfer function of the FET gate voltage. When the switch SW1 is turned off and the capacitor C1 is charged by the voltage generated at both ends of the switch SW1, the gate voltage of the MOSFET T1 is lowered, and the MOSFET T1 is turned off so that a current flows through the MOSFET T1. Disappear.

The diode D1 connected in parallel with the resistor R1 of the DC circuit 100 is used for discharging the charge accumulated in the capacitor C1 in a short time without going through the resistor R1 when the switch SW1 shifts from the off state to the on state. Provided.

In the DC circuit 100, the diode D1 is provided in parallel with the resistor R1, so that the voltage integration function of the DC circuit 100 can be restored in a short time even if the connection of the switch SW1 causes chattering or the like. . The resistor R1 supplies a voltage to the gate terminal of the MOSFET T1, and the voltage supply time is determined by the product relationship between the capacitance of the capacitor C1 and the resistance value of the resistor R1.

The DC circuit 100 has a switch FS1 and a fuse F1 as shown in FIG. The switch FS1 is in a state where the terminal a1 which is a common terminal and the terminal a2 which is a fixed contact are electrically connected by a movable contact when the switch FS1 is normal (which means that the fuse F1 is not blown). Yes. The movable contact of the switch FS1 has an elastic force, and when the fuse F1 is blown as will be described later, the terminals a1 and a2 are not electrically connected.

The fuse F1 is blown when an excessive current flows in the sub system in which the MOSFET T1 is provided. When the fuse F1 is blown, the switch FS1 loses the holding force by the fuse F1 and electrically opens the terminal a1 and the terminal a2.

FIG. 2 is an explanatory diagram showing the DC circuit 100 in a state where the fuse F1 is blown. When an excessive current flows through the fuse F1 and the fuse F1 is blown, the switch FS1 loses the holding force by the fuse F1 as shown in FIG. 2, and the terminals a1 and a2 are electrically opened.

In the DC circuit 100 shown in FIG. 1, the rated energization time of the fuse F <b> 1 (time until fusing) after the switch SW <b> 1 is switched from the on state to the off state and the MOSFET T <b> 1 is turned on. If the MOSFET T1 is turned off in a shorter time, the fuse F1 is not blown.

However, the MOSFET T1 is turned off in a time shorter than the fusing time of the fuse F1 after the switch SW1 is switched from the on state to the off state due to an abnormal state, that is, the MOSFET T1 breaks down and the MOSFET T1 is turned on. If not, current continues to flow through the fuse F1, and the fuse F1 is blown.

FIG. 3 is an explanatory diagram showing the time change of the current flowing through the fuse F1 in a graph. FIG. 3 shows the time change of the current I1 flowing through the fuse F1 when the DC circuit 100 is normal and the time change of the current I2 flowing through the fuse F1 when the DC circuit 100 is abnormal. .

In a normal state of the DC circuit 100, even if a current exceeding the rated current flows, the current I1 decreases in a time shorter than the rated energization time (time until the fuse F1 is blown). Therefore, when the DC circuit 100 is normal, the fuse F1 is not blown. However, when the DC circuit 100 is in an abnormal state, the MOSFET T1 is not turned off and the current continues to flow. When a current exceeding the rated current is exceeded and the current exceeding the rated current flows, the fuse F1 is finally blown and finally the current flows. I2 decreases.

In other words, the DC circuit 100 uses the fact that the fuse F1 is not blown if a current exceeding the rated current flows even if the current is shorter than the rated energization time, so that even if the switch SW1 is switched from the on state to the off state, The occurrence of arc discharge can be suppressed. Further, in the case where the DC circuit 100 is not in a normal state due to a failure of the MOSFET T1, the switch FS1 is opened due to the blow of the fuse F1, and re-energization in the main system and the sub system from the DC power supply is performed. Can be deterred.

FIG. 4 is an explanatory diagram showing the state of the switch FS1 and the fuse F1 in a normal state. FIG. 5 is an explanatory diagram showing the state of the switch FS1 and the fuse F1 when the fuse F1 is blown.

As shown in FIG. 4, in a state in which the fuse F1 is not blown, the switch FS1 is electrically connected between the terminal a1 and the terminal a2 by the fuse F1. However, when the fuse F1 is blown, the switch FS1 loses the holding force by the fuse F1, and the terminals a1 and a2 are electrically opened.

Note that the movable contact of the switch FS1 may have a structure bent near the middle as shown in FIG. By having such a bent structure, the switch FS1 can easily open the terminals a1 and a2 when the fuse F1 is blown.

FIG. 6 is an explanatory diagram showing the state of the switch FS1 and the fuse F1 in a normal state. FIG. 7 is an explanatory diagram showing the state of the switch FS1 and the fuse F1 when the fuse F1 is blown.

As shown in FIGS. 6 and 7, the fuse F1 may be connected further to the movable contact of the switch FS1. As described above, the fuse F1 is configured to be connected further before the movable contact of the switch FS1, so that the holding force applied to the fuse F1 can be weakened and a soft material can be used as the material of the fuse F1. .

Another fuse may be provided between the terminal a1 on the fixed contact side of the switch FS1 and one end of the fuse F1 so as to be in parallel with the fuse F1.

FIG. 8 is an explanatory diagram showing the state of the switch FS1, the switch FS1, and the fuses F1, F2 in a normal state. FIG. 9 is an explanatory diagram showing the state of the switch FS1 and the fuses F1, F2 when the fuses F1, F2 are blown.

∙ The resistance of the fuse varies depending on the metal used. By providing the fuses F1 and F2 as shown in FIG. 8, the holding force of the movable contact of the switch FS1 is strengthened, and the enlargement of the fuse F1 is avoided. By providing two fuses in this way, even if the allowable cut-off current of the voltage integrating circuit is changed, only the change of the fuse F2 is required, so that the change of the configuration can be minimized. The fuse F2 may have the same rated energization time as the fuse F1, but may have a different rated energization time.

A capacitor may be provided between the terminal a1 on the fixed contact side of the switch FS1 and one end of the fuse F1 so as to be in parallel with the fuse F1.

FIG. 10 is an explanatory diagram showing the state of the switch FS1, the fuse F1, and the capacitor C11 in a normal state.

The capacitor C11 is provided in order to accumulate a charge by diverting a part of the pulsed current that flows when the switch SW1 is turned off. The electric charge accumulated in the capacitor C11 is gradually released through the fuse F1.

FIG. 11 is an explanatory diagram showing the time change of the current flowing through the fuse F1 and the capacitor C11 in a graph. FIG. 11 shows the time change of the currents I11 and I13 flowing through the fuse F1 and the capacitor C11 when the DC circuit 100 is normal, and the time change of the current I12 flowing through the fuse F1 when the DC circuit 100 is abnormal. It is shown.

When the DC circuit 100 is in a normal state, an amount of current indicated by reference numeral I11 flows through the fuse F1, and an amount of current indicated by reference numeral I13 flows through the capacitor C11. Compared with the transition of the current shown in FIG. 3, it can be seen that the amount of current flowing through the fuse F1 is reduced by providing the capacitor C11. That is, the deterioration of the fuse F1 can be suppressed by providing the capacitor C11.

FIG. 12 is an explanatory diagram illustrating another configuration example of the DC circuit according to the embodiment of the present disclosure. FIG. 12 shows a DC circuit 100 for combining a solid state relay (SSR, semiconductor relay) with a mechanical relay and switching between supply and interruption of DC power by turning on and off the mechanical relay. This is an example of the configuration.

The DC circuit 100 shown in FIG. 12 includes an SSR 130, a mechanical relay RY1, diodes D21, D22, and D23, capacitors C21 and C22, and a resistor R21. The DC circuit 100 allows a current to flow through the main system and the sub system that are parallel in the path through which the DC flows. A system in which the SSR 130 is provided is a main system, and a system in which the mechanical relay RY1 is provided is a sub system.

The mechanical relay RY1 operates so as to switch contacts using an electromagnetic force generated by a current flowing from the terminal V + to the terminal V−. The mechanical relay RY1 is connected to the contact 1b when no current flows from the terminal V + to the terminal V-, and is connected to the contact 1a using electromagnetic force when the current flows from the terminal V + to the terminal V-. . Although not shown in FIG. 12, a DC power supply for supplying DC power to the terminal V + may be provided.

The SSR 130 is provided on the power supply path from the terminal A to the terminal B. In the present embodiment, the SSR 130 is configured to be turned on when a high voltage is applied to the control terminal, and to be turned off when a low voltage is applied to the control terminal.

When no current flows from the terminal V + to the terminal V−, no current flows through the mechanical relay RY1, and therefore the mechanical relay RY1 is connected to the contact 1b. Therefore, the contact 1b of the mechanical relay RY1 is in the closed state, and the contact 1a is in the open state.

Thereafter, when a voltage is applied to the terminal V + and a current flows from the terminal V + to the terminal V−, the mechanical relay RY1 gradually generates an electromagnetic force. When the electromagnetic force generated by the mechanical relay RY1 reaches a certain level, the mechanical relay RY1 releases the connection with the contact 1b.

When the electromagnetic force further increases, the mechanical relay RY1 is connected to the contact 1a, but chattering occurs when connecting to the contact 1a. When a voltage is applied to the terminal V +, the voltage is applied to the control terminal of the SSR 130, and the SSR 130 is turned on. When a current flows from the terminal V + to the terminal V−, charge is accumulated in the capacitor C21 through the diode D21.

After that, when no voltage is applied to the terminal V + and no current flows from the terminal V + to the terminal V−, the mechanical relay RY1 gradually reduces the electromagnetic force. When the electromagnetic force generated by the mechanical relay RY1 starts to decrease, the mechanical relay RY1 releases the connection with the contact 1a. When the electromagnetic force further decreases, the mechanical relay RY1 is connected to the contact 1b, but chattering occurs at the time of connection with the contact 1b.

At this time, it is desirable that the capacitor C21 can store enough power to turn on the SSR 130 until the mechanical relay RY1 is connected to the contact 1b. At this time, the diode D22 is released from the reverse bias and becomes conductive, and the capacitor C22 operates through the coil of the mechanical relay RY1.

That is, the capacitor C22 absorbs chattering when the mechanical relay RY1 is connected to the contact 1b. Capacitor C22 also forms a discharge circuit for capacitor C21 through diode D23 and absorbs the surge of mechanical relay RY1.

Therefore, in the DC circuit 100 shown in FIG. 12, no current flows from the terminal V + to the terminal V−, and even when the mechanical relay RY1 is disconnected from the contact 1a, the generation of arc is suppressed and the surge can be absorbed. I can do it. In addition, the DC circuit 100 shown in FIG. 12 has four terminals and can be connected in the same way as a general relay, so that it can be used in place of an existing relay.

The DC circuit 100 shown in FIG. 12 includes a switch FS1 and a fuse F1. When the semiconductor switch of the SSR 130 fails and does not normally shift to the OFF state, the fuse F1 is eventually blown by the current flowing from the terminal A. When the fuse F1 is blown, the switch FS1 on the path on the contact 1a side of the mechanical relay RY1 is turned off.

When the switch FS1 on the path on the contact 1a side of the mechanical relay RY1 is turned off, current does not flow from the terminal A to the terminal B even if the mechanical relay RY1 is connected to the contact 1a side. Therefore, the DC circuit 100 shown in FIG. 12 can suppress re-energization by the mechanical relay RY1 even if the semiconductor switch of the SSR 130 fails and does not normally shift to the OFF state.

FIG. 13 is an explanatory diagram showing the change over time of the current flowing through the fuse F1 of the DC circuit 100 shown in FIG. FIG. 13 shows the time change of the current I21 flowing through the fuse F1 when the DC circuit 100 is normal and the time change of the current I22 flowing through the fuse F1 when the DC circuit 100 is abnormal. .

In the normal state of the DC circuit 100, even if a current exceeding the rated current flows, the current I21 decreases in a time shorter than the rated energization time (time until fusing) of the fuse F1. Therefore, when the DC circuit 100 is normal, the fuse F1 is not blown. However, when the DC circuit 100 is in an abnormal state, the current continues to flow without the SSR 130 being turned off, and when the current exceeding the rated current exceeds the rated current, the fuse F1 is finally blown and the current I2 is finally reached. Decreases.

In other words, the DC circuit 100 uses the fact that the fuse F1 is not blown if a current exceeding the rated current flows even if the current is shorter than the rated energization time, so that even if the switch SW1 is switched from the on state to the off state, The occurrence of arc discharge can be suppressed. Further, in the DC circuit 100, when the SSR 130 is not in a normal state due to a failure or the like, the switch FS1 is opened due to the blow of the fuse F1, and re-energization in the main system and the sub system from the DC power supply is suppressed. can do.

FIG. 14 is an explanatory diagram showing a connection example of the switch FS1 and the fuses F1 and F2. As shown in FIG. 14, a fuse F2 may be provided in parallel with the switch FS1 between the terminal a1 on the common terminal side of the switch FS1 and the terminal a2 on the fixed contact side. When the MOSFET T1 is not in a normal state due to a failure or the like, the fuse F1 is blown by temporarily passing an excessive current through the fuse F1. The configuration shown in FIG. 14 is characterized in that the generation of an arc when the fuse F1 is blown and the switch FS1 is opened is suppressed by supplying power to the fuse F2.

FIG. 15 is an explanatory view showing a state where both the fuses F1 and F2 shown in FIG. 14 are blown. When an excessive current temporarily flows through the fuse F1, the fuse F1 is blown, and when the switch FS1 is opened, a current further flows through the fuse F2, and the fuse F2 is also blown. By operating the fuses F1 and F2 in this way, it is possible to suppress the occurrence of an arc when the fuse F1 is blown and the switch FS1 is opened.

FIG. 14 shows an example in which a fuse F2 is provided in parallel with the switch FS1. In this example, the fuse F1 may be connected from the tip of the movable contact of the switch FS1 as shown in FIG. Further, as shown in FIG. 10, in addition to a configuration in which a capacitor is provided in parallel with the fuse F1 between the terminal a1 on the fixed contact side of the switch FS1 and one end of the fuse F1, in parallel with the switch FS1. The fuse F2 may be provided.

FIG. 16 is an explanatory diagram illustrating another configuration example of the DC circuit according to an embodiment of the present disclosure. FIG. 16 shows an example of the DC circuit 100 configured to suppress the occurrence of arcs even when the MOSFET T1 constituting the voltage integrating circuit is in a short state or in an open state. It is.

FIG. 16 shows a DC circuit 100 in which a resistor-equipped thermoprotector THP1 using a thermal fuse F1 is connected to one contact, for example, a fixed contact, of a switch SW1 that cuts off DC current.

The operation of the DC circuit 100 shown in FIG. 16 will be described. When the switch SW1 is in the OFF state, the MOSFET T1 is also in the OFF state, so that no current flows from the DC power supply side (IN) to the load side (OUT). Thereafter, when the switch SW1 is operated and the switch SW1 is turned on, a current flows from the DC power supply side (IN) to the load side (OUT). In this state, the MOSFET T1 is continuously turned off. Therefore, no current flows through the MOSFET T1.

After that, when the switch SW1 is operated and the switch SW1 is turned off, no current flows from the DC power supply side (IN) to the load side (OUT). At this time, the voltage at both ends of the switch SW1 generated when the switch SW1 is turned off (by disconnecting both ends of the switch SW1) induces the gate voltage of the MOSFET T1 through the capacitor C1, and the MOSFET Turn T1 on. When the MOSFET T1 is turned on, a current flows in the direction of decreasing the voltage across the switch SW1 from the DC power source toward the load 10.

The MOSFET T1 is turned on, and the current flows in the direction of decreasing the voltage at both ends of the switch SW1 from the DC power supply side (IN) to the load side (OUT), thereby reducing the voltage at both ends of the switch SW1. The By reducing the voltage across the switch SW1, the switch SW1 does not cause arc discharge even when the switch SW1 is turned off.

The diode DZ1 connected in parallel to the resistor R2 of the DC circuit 100 is for discharging the charge accumulated in the capacitor C1 in a short time without going through the resistor R2 when the switch SW1 is shifted from the off state to the on state. Provided.

Here, when the MOSFET T1 fails in a short state, the current continues to flow through the resistor R3 of the thermoprotector THP1 with a resistor, and the resistor R3 generates heat. When the temperature of the resistor R3 becomes equal to or higher than a predetermined fusing temperature, the thermal fuse F1 is blown. When the thermal fuse F1 is blown, the voltage applied to the switch SW1 is suppressed.

Also, if the switch SW1 is turned off while the MOSFET T1 is in an open state and has failed, no current flows through the MOSFET T1. However, since the thermal fuse F1 is provided, the thermal fuse F1 is melted by arc heat generated when the switch SW1 is turned off. Therefore, the DC circuit 100 shown in FIG. 16 can safely cut off the DC current even if the switch SW1 is turned off while the MOSFET T1 is in an open state and has failed.

FIG. 17 is an explanatory diagram illustrating another configuration example of the DC circuit according to an embodiment of the present disclosure. FIG. 17 shows a configuration example of the DC circuit 100 in which the fuse F2 is provided in parallel with the resistor R3 in the DC circuit 100 shown in FIG. Thus, by providing the fuse F2 in parallel with the resistor R3, when the MOSFET T1 fails in a short state, the fuse F2 is first blown. In the DC circuit 100 shown in FIG. 17, the voltage applied to the switch SW1 is suppressed by blowing the fuse F2.

FIG. 18 is an explanatory diagram showing another configuration example of the switch circuit 110. FIG. 18 shows a switch including a current fuse Fc1 provided between terminals a and b, a thermoprotector Ftp1 provided between terminals a and b and c, and diodes D31 and D32. Circuit. The thermoprotector Ftp1 is provided between the temperature fuses Ft1 and Ft2 connected in series, between the temperature fuses Ft1 and Ft2, and the terminal c, and includes a resistor R1. The resistor R1 is provided to heat the thermal fuses Ft1 and Ft2. The terminal c is connected to a circuit through which a current flows for a short period of time when it is normal, such as the voltage integration circuit described above.

The current fuse Fc1 and the current fuse Fc2 connected in parallel with the resistor R1 are direct current fuses, and an arc at the time of fusing occurs only inside the fuse housing, and is digested by an arc extinguishing agent after the arc is generated. Use what has a structure.

Only by connecting the temperature fuses Ft1, Ft2 and the current fuse Fc1 in parallel, the current is always shunted according to the respective resistance values. There is a possibility that deterioration of the current fuse Fc1 is accelerated by always diverting the current. The internal resistance of a general temperature fuse is about 1.5 mΩ to 15 mΩ, and the internal resistance of the current fuse is 120 mΩ in the case of 1 A rating and 16 mΩ in the case of 5 A rating. Therefore, depending on the combination of fuses, half may flow through the current fuse.

Therefore, in the configuration example of the switch circuit shown in FIG. 18, two diodes D31 and D32 are provided. The two diodes D31 and D32 differ in the direction in which current flows as shown in FIG. Note that the two diodes D31 and D32 may be replaced with bidirectional diodes.

By providing the two diodes D31 and D32, the current fuse Fc1 is only generated when a voltage higher than the forward voltage (for example, approximately 0.65 V) of the two diodes D31 and D32 is generated by the resistors of the thermal fuses Ft1 and Ft2. Current begins to flow. Therefore, when the internal resistance of the thermal fuses Ft1 and Ft2 is 15 mΩ, for example, a current of 40 A or more needs to flow, and in normal use, the current fuse Fc1 does not flow, and the thermal fuses Ft1 and Ft2 are blown.

By providing the two diodes D31 and D32, the current fuse Fc1 can be prevented from deteriorating by being shunted to the current fuse Fc1 only when the internal resistance values of the thermal fuses Ft1 and Ft2 change.

FIG. 19 is an explanatory diagram showing an example of a current flowing between terminals a and b and a current flowing in terminal c of the circuit shown in FIG. A pulsed current having a current value of the same level as the amount of current flowing between terminals a and b flows through terminal c in FIG. In the state where the current flows intermittently, the current fuse Fc2 has a capacity that does not blow, and the heat generation of the resistor R1 due to the shunt causes the temperature fuses Ft1 and Ft2 to have a heat capacity that does not blow.

However, if a current flows constantly to the terminal c from time t1 due to some abnormality, the current fuse Fc2 is blown at time t2. When the current fuse Fc2 is blown, the temperature fuses Ft1 and Ft2 are blown at a time t3 due to heat generated by the current diverted to the resistor R1. When the thermal fuses Ft1 and Ft2 are blown, the current between the terminals ab is cut off, and the current is shunted to the current fuse Fc1. Eventually, the current fuse Fc1 is blown at time t4 by the current between the terminals a and b.

Note that the relationship between the times t1, t2, t3, and t4 shown in FIG. 19 is an example, and the time at which each fuse blows is not limited to such an example.

The current fuse Fc1 has a resistance value larger than the sum of the resistance values of the thermal fuses Ft1 and Ft2 due to its characteristics. The circuit shown in FIG. 18 normally utilizes the fact that the current flowing through the current fuse Fc1 is very small and therefore does not blow. For example, as the current fuse Fc1, a fuse that is blown at 1A is selected.

Assuming that the current normally flowing between the terminals ab is 2 A, an arc is generated when the thermal fuses Ft1 and Ft2 are blown, but the arc energy is absorbed by the current fuse Fc1. Then, since the arc energy changes in shape to the fusing of the current fuse Fc1, the circuit shown in FIG. 18 can suppress the generation of an arc even when a current constantly flows through the terminal c.

FIG. 20 is an explanatory diagram illustrating a functional configuration example of the moving body 40 including the DC circuit 100. The moving body 40 may be, for example, a moving body that uses gasoline as a power source, such as a gasoline car, and uses a chargeable / dischargeable battery as a main power source, such as an electric vehicle, a hybrid vehicle, and an electric motorcycle. It may be a body. FIG. 20 illustrates an example in which the moving body 40 includes a battery 210 and a driving unit 220 that is driven by electric power supplied from the battery. The drive unit 220 may include, for example, equipment provided in the vehicle such as a wiper, a power window, a light, a car navigation system, and an air conditioner, and a device that drives the moving body 40 such as a motor.

20 is provided with a DC circuit 100 in the middle of a path through which DC power is supplied from the battery 210 to the drive unit 220. 20 is provided with a DC circuit 100 on a path through which DC power is supplied from the battery 210 to the drive unit 220. For example, when the battery 210 is temporarily attached or detached, arc discharge occurs. Can be suppressed.

FIG. 20 illustrates an example of the moving body 40 provided with only one DC circuit 100, but the present disclosure is not limited to such an example. That is, a plurality of DC circuits 100 may be provided in the middle of a path through which DC power is supplied. Further, the DC circuit 100 may be provided not only in the middle of a path in which DC power is supplied from the battery 210 to the drive unit 220 but also in another place, for example, in the middle of a path when charging the battery 210 with DC power. . The moving body 40 can safely charge the battery 210 with DC power by providing the DC circuit 100 in the middle of the path when charging the battery 210 with DC power.

<2. Summary>
As described above, according to the embodiment of the present disclosure, by suppressing the voltage generated between the electrodes when the DC power is cut, the arc discharge is performed when the DC power is cut without reducing the power efficiency when the DC power is supplied. There is provided a DC circuit 100 capable of suppressing the occurrence of the occurrence of the problem with a small-scale configuration.

In the DC circuit 100 according to the embodiment of the present disclosure, when the MOSFET T1 is not in a normal state due to failure or the like, the switch FS1 is opened due to the fuse F1 being blown, and the main system and the sub-system from the DC power supply are opened. Re-energization in the system can be suppressed.

The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, but the technical scope of the present disclosure is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field of the present disclosure can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that it belongs to the technical scope of the present disclosure.

In addition, the effects described in this specification are merely illustrative or illustrative, and are not limited. That is, the technology according to the present disclosure can exhibit other effects that are apparent to those skilled in the art from the description of the present specification in addition to or instead of the above effects.

The following configurations also belong to the technical scope of the present disclosure.
(1)
A first current path and a second current path provided in parallel in a path through which direct current flows;
A circuit for causing a pulsed current to flow for a predetermined period when a direct current is interrupted in the second current path using a first switch provided on the first current path;
A fuse provided in front of the first switch;
A resistor provided between the fuse and the circuit;
With
The fuse is a DC circuit having a rating that does not blow at the temperature of the resistor due to the flow of a rated energization current during the rated energization time of the circuit.
(2)
The DC circuit according to claim 1, wherein the circuit is a circuit that suppresses an amount of direct current flowing through the first current path.
(3)
The circuit is
A switching element that is provided on the first current path and that is turned on when direct current is no longer supplied in the second current path and reduces a current flowing to the source side;
Capacitance element that starts charging when DC is no longer supplied through the first current path and increases the gate voltage of the switching element after DC is no longer supplied through the second current path;
A resistive element for setting a time for applying a voltage to the gate terminal of the switching element together with the capacitive element;
The DC circuit according to claim 2, comprising:
(4)
A first current path and a second current path provided in parallel in a path through which direct current flows;
A first current fuse provided on the first current path;
On the first current path, at least two thermal fuses provided in parallel with the first current fuse;
Two diodes provided alternately in parallel downstream of the first current fuse and the at least two thermal fuses;
A resistor provided between the two thermal fuses and a circuit for passing a pulsed current for a predetermined period when a direct current is interrupted in the second current path;
A second current fuse provided in parallel with the resistor;
With
The second current fuse has a rating that does not blow at the temperature of the resistor due to the flow of a rated energization current during the rated energization time of the circuit.
(5)
A first current path and a second current path provided in parallel in a path through which direct current flows;
A circuit for causing a pulsed current to flow for a predetermined period when a direct current is interrupted in the second current path using a first switch provided on the first current path;
A second switch provided before the first switch, wherein the connection is maintained by the tension of the fuse;
With
When the fuse is blown, the second switch is opened,
The fuse is a DC circuit having a rating that is not blown by a rated energization current during a rated energization time of the circuit.
(6)
The circuit according to (5), wherein the circuit is a circuit that suppresses an amount of direct current flowing through the first current path.
(7)
The circuit is
A switching element that is provided on the first current path and that is turned on when direct current is no longer supplied in the second current path and reduces a current flowing to the source side;
Capacitance element that starts charging when DC is no longer supplied through the first current path and increases the gate voltage of the switching element after DC is no longer supplied through the second current path;
A resistive element for setting a time for applying a voltage to the gate terminal of the switching element together with the capacitive element;
The DC circuit according to (6), comprising:
(8)
The circuit is
A semiconductor relay which is provided on the first current path and which switches between supply and interruption of a direct current from a direct current power supply;
A mechanical relay provided on the second current path and connected in parallel with the semiconductor relay to switch supply and interruption of a direct current from the direct current power source;
With
The DC circuit according to (6), which is a circuit that suppresses chattering of the mechanical relay when DC is cut off by the mechanical relay.
(9)
The DC circuit according to any one of (5) to (9), wherein the fuse connects the movable contact of the second switch and the circuit when the fuse is not blown.
(10)
The DC circuit according to (9), wherein the fuse is connected to the circuit from between a common terminal of the second switch and a movable contact.
(11)
The DC circuit according to (9), wherein the fuse is connected to the circuit from a point between a common terminal of the second switch and a movable contact.
(12)
The DC circuit according to any one of (9) to (11), further including a second fuse between the common terminal of the second switch and the circuit.
(13)
The DC circuit according to (12), wherein the second fuse has a rating characteristic different from that of the fuse.
(14)
The DC circuit according to (9), further including a capacitor between the common terminal of the second switch and the circuit.
(15)
The DC circuit according to (5), further including a second fuse in parallel with the second switch.
(16)
A moving body comprising the DC circuit according to any one of (1) to (15).
(17)
A battery for supplying DC power;
A drive unit driven by DC power supplied from the battery;
At least one DC circuit according to any one of (1) to (15) provided between the battery and the drive unit;
A power supply system comprising:

100 DC circuit

Claims

A first current path and a second current path provided in parallel in a path through which direct current flows;
A circuit for causing a pulsed current to flow for a predetermined period when a direct current is interrupted in the second current path using a first switch provided on the first current path;
A fuse provided in front of the first switch;
A resistor provided between the fuse and the circuit;
With
The fuse is a DC circuit having a rating that does not blow at the temperature of the resistor due to the flow of a rated energization current during the rated energization time of the circuit.
2. The DC circuit according to claim 1, wherein the circuit is a circuit that suppresses the amount of DC flowing through the first current path.
The circuit is
A switching element that is provided on the first current path and that is turned on when direct current is no longer supplied in the second current path and reduces a current flowing to the source side;
Capacitance element that starts charging when DC is no longer supplied through the first current path and increases the gate voltage of the switching element after DC is no longer supplied through the second current path;
A resistive element for setting a time for applying a voltage to the gate terminal of the switching element together with the capacitive element;
The DC circuit according to claim 2, comprising:
A first current path and a second current path provided in parallel in a path through which direct current flows;
A first current fuse provided on the first current path;
On the first current path, at least two thermal fuses provided in parallel with the first current fuse;
Two diodes provided alternately in parallel downstream of the first current fuse and the at least two thermal fuses;
A resistor provided between the two thermal fuses and a circuit for passing a pulsed current for a predetermined period when a direct current is interrupted in the second current path;
A second current fuse provided in parallel with the resistor;
With
The second current fuse has a rating that does not blow at the temperature of the resistor due to the flow of a rated energization current during the rated energization time of the circuit.
A first current path and a second current path provided in parallel in a path through which direct current flows;
A circuit for causing a pulsed current to flow for a predetermined period when a direct current is interrupted in the second current path using a first switch provided on the first current path;
A second switch provided before the first switch, wherein the connection is maintained by the tension of the fuse;
With
When the fuse is blown, the second switch is opened,
The fuse is a DC circuit having a rating that is not blown by a rated energization current during a rated energization time of the circuit.
The DC circuit according to claim 5, wherein the circuit is a circuit that suppresses the amount of direct current flowing through the first current path.
The circuit is
A switching element that is provided on the first current path and that is turned on when direct current is no longer supplied in the second current path and reduces a current flowing to the source side;
Capacitance element that starts charging when DC is no longer supplied through the first current path and increases the gate voltage of the switching element after DC is no longer supplied through the second current path;
A resistive element for setting a time for applying a voltage to the gate terminal of the switching element together with the capacitive element;
The DC circuit according to claim 6, comprising:
The circuit is
A semiconductor relay which is provided on the first current path and which switches between supply and interruption of a direct current from a direct current power supply;
A mechanical relay provided on the second current path and connected in parallel with the semiconductor relay to switch supply and interruption of a direct current from the direct current power source;
With
The direct current circuit according to claim 6, wherein the direct current circuit is a circuit that suppresses chattering of the mechanical relay when the mechanical relay interrupts direct current.
6. The DC circuit according to claim 5, wherein the fuse connects the movable contact of the second switch and the circuit when the fuse is not blown.
10. The DC circuit according to claim 9, wherein the fuse is connected to the circuit from between a common terminal and a movable contact of the second switch.
10. The DC circuit according to claim 9, wherein the fuse is connected to the circuit from a point between a common terminal of the second switch and a movable contact.
10. The DC circuit according to claim 9, further comprising a second fuse between the common terminal of the second switch and the circuit.
The DC circuit according to claim 12, wherein the second fuse has a rating characteristic different from that of the fuse.
The DC circuit according to claim 9, further comprising a capacitor between the common terminal of the second switch and the circuit.
The DC circuit according to claim 5, further comprising a second fuse in parallel with the second switch.
A moving body comprising the DC circuit according to claim 1.
A battery for supplying DC power;
A drive unit driven by DC power supplied from the battery;
At least one DC circuit according to claim 1 or 4 provided between the battery and the drive unit;
A power supply system comprising: