JP3193186B2 - DC connection control device and DC connection release control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for connecting a DC output of a DC power supply device such as a DC / DC converter in parallel, and controls the connection and opening operation of the DC output regardless of whether the power supply is being started or stopped. The present invention relates to a DC connection release control device.

[0002]

2. Description of the Related Art Conventionally, a DC power supply system in which the DC outputs of two DC / DC converters are connected employs one of the following two systems.

1) System without parallel connection In a DC power supply system without parallel connection as shown in FIG. 5, load contactors 2 and 3 are respectively connected to the load sides of DC / DC converters 4 and 5 in the same manner as an AC output power supply system. And a power contactor 1 is provided between the DC / DC converters 4 and 5, and when one of the DC / DC converters stops, the load contactor on the converter side is opened and the power supply / contactor 1 is turned on. By doing so, the other D
Power was supplied from the C / DC converter.

However, in the case of this DC power supply system without parallel connection, the power is interrupted from the time when one DC / DC converter stops to the time when the power supply / reception operation is completed. However, there is a problem that the redundancy for the uninterruptible power supply system due to the parallel connection is lost.

2) System connected in parallel In the DC power supply system connected in parallel shown in FIG.
Even if any one of the C / DC converters 4 and 5 is stopped, power can be supplied from the remaining DC / DC converters without any change. Therefore, there is an advantage that the operation can be continued without a power failure on the load side. is there.

However, in the conventional parallel-connected DC power supply system, each of the DC power supply devices such as the DC / DC converters 4 and 5 is provided with the large-capacity electrolytic capacitors 6 and 7 on the load side. (For example, when one power supply is stopped and the other power supply is activated, or when the load capacity of one power supply is large and the load capacity of the other power supply is large) When these DC power supplies are connected, a large current flows from the power supply with the higher voltage to the power supply with the lower voltage to charge the electrolytic capacitor, which causes welding at the circuit connection and shortens the life of the electrolytic capacitor. May cause
In order to avoid this, it is necessary to temporarily stop all power supply units to be connected in the case of parallel connection, and then perform the connection operation. When connecting and disconnecting, the power supply to the load side will stop. There was a problem that the service deteriorated.

[0007]

As described above, in the case of a conventional DC power supply system in which DC power supplies are not connected in parallel, a period from when one DC power supply is stopped to when the power supply / reception operation is completed is completed. Because of the power failure, there has been a problem that the redundancy for the uninterruptible power supply system by the parallel connection, which is a great advantage of the DC power supply system, is lost.

In the case of a conventional parallel-connected DC power supply system, since each DC power supply has a large-capacity electrolytic capacitor on the load side, there is a case where there is a slight voltage difference on the output side (for example, If one power supply is down and the other power supply is up, or if the load capacity of one power supply is high and the load capacity of the other power supply is low, these DC power supplies are When connected, a large current flows from the high voltage power supply to the low power supply to charge the electrolytic capacitor, which may cause welding at the connection points of the circuit and shorten the life of the electrolytic capacitor. When connecting a DC power supply, it is necessary to temporarily stop all power supply units to be connected before performing the connection operation. Service power supply is stopped to have a problem to decrease.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and in a DC power supply system connected in parallel, a connecting operation or a connecting / opening without stopping all the DC power supply units to be connected. It is an object to provide a DC connection control device and a DC connection release control device that can be operated.

[0010]

According to a first aspect of the present invention, there is provided a DC connection control device comprising: a first DC electromagnetic contactor having two or more poles for connecting and opening two DC power supply devices; and one of the DC power supply devices. Connecting and opening between the first DC electromagnetic contactor and the second DC electromagnetic contactor
And a charging resistor for charging an electrolytic capacitor of each of the two DC power supply devices provided in parallel with the second DC electromagnetic contactor, and a voltage on both sides of the second DC electromagnetic contactor. A voltage difference detector for detecting a difference and a first DC electromagnetic contactor are turned on in response to a connection command between two DC power supply devices from outside, and thereafter, the voltage difference detected by the voltage difference detector is a predetermined value. A control unit for performing connection control for turning on the second DC electromagnetic contactor when the following occurs.

A DC connection and disconnection control device according to a second aspect of the present invention provides a first DC electromagnetic contactor having two or more poles for connecting and disconnecting two DC power supply devices, one of the DC power supply devices and a first DC power supply. A second DC electromagnetic contactor that connects and opens the electromagnetic contactor, and is provided in parallel with the second DC electromagnetic contactor.
A charging resistor for charging an electrolytic capacitor of each of the two DC power supplies, a voltage difference detector for detecting a voltage difference between both sides of the second DC electromagnetic contactor, and a connection between the two external DC power supplies; Receiving a command, turning on the first DC electromagnetic contactor, and then turning on the second DC electromagnetic contactor when the voltage difference detected by the voltage difference detector falls below a predetermined value; Receiving a command to open between the two DC power supply devices from the second DC power supply device, opening the second DC electromagnetic contactor, and thereafter performing a release control to open the first DC electromagnetic contactor. .

According to a third aspect of the present invention, there is provided a DC connection control device comprising:
A DC electromagnetic contactor having two or more poles connecting and opening two DC power supply devices, a charging transistor for intermittently controlling a charging current flowing through the respective electrolytic capacitors of the two DC power supply devices via the DC electromagnetic contactor, A current detector that detects the current flowing through the charging transistor and a DC electromagnetic contactor are turned on in response to an external connection command between the two DC power supplies, and then the current detection value of the current detector is A control unit for performing connection control for gradually increasing the base current of the charging transistor and conducting the current while monitoring the current so as not to exceed a predetermined value.

According to a fourth aspect of the present invention, there is provided a DC connection release control device for connecting and disconnecting two DC power supply devices, a DC electromagnetic contactor having two or more poles, and two DC power supply devices via the DC electromagnetic contactor, respectively. A charging transistor for intermittently controlling the charging current flowing through the electrolytic capacitor, a current detector for detecting a current flowing to the charging transistor, and a DC electromagnetic contactor receiving a connection command between two DC power supply devices from outside. And then control the current detection value of the current detector so that it does not exceed a certain value while gradually increasing the base current of the charging transistor to conduct. While monitoring the current detection value of the current detector in response to the open command between the power supply devices, gradually lower the base current of the charging transistor until the current detection value is equal to or less than the predetermined value, and turn off the base. , Then, in which a control unit that performs the opening control for opening the DC electromagnetic contactor.

[0014]

In the DC connection control device according to the first aspect of the present invention, when the two DC power supply devices are connected, the control unit first receives the connection command between the two DC power supply devices and receives the command from the outside. The first DC electromagnetic contactor is connected by turning on the electromagnetic contactor, and then performing the connection control of turning on the second DC electromagnetic contactor when the voltage difference detected by the voltage difference detector becomes a predetermined value or less. When the DC power supply is turned on, the charging resistor suppresses the large current that is about to flow from the active DC power supply into the electrolytic capacitor on the DC power supply that had been stopped until then. It is possible to control so as to flow into the electrolytic capacitor on the power supply device side, and it is possible to connect the two DC power supply devices in parallel without stopping the DC power supply device being started.

In the DC connection opening control device according to the second aspect of the present invention, when the two DC power supply devices are connected, the control unit first receives the connection command between the two DC power supply devices and receives the command from the outside. The first DC electromagnetic contactor is turned on, and then the second DC electromagnetic contactor is turned on when the voltage difference detected by the voltage difference detector becomes equal to or less than a predetermined value. When the contactor is turned on, the large current that tries to flow from the active DC power supply into the electrolytic capacitor on the DC power supply that had been stopped until then is suppressed by the charging resistor, and the current gradually stops. It can be controlled so that it flows into the electrolytic capacitor on the DC power supply side, and even if it is a small-capacity DC electromagnetic contactor, the two DC power supplies can be connected in parallel without stopping the DC power supply being started But Kill.

When the two DC power supply units are opened, the control unit first opens the second DC electromagnetic contactor in response to an external open command between the two DC power supply units. By performing the opening control to open the DC electromagnetic contactor of the first, a breaking current flows between both DC power supply devices through the charging resistor by opening the second DC electromagnetic contactor,
Since the first DC electromagnetic contactor is opened after the current is sufficiently reduced, a large breaking current does not flow at the time of opening, and even if current flows between the two DC power supplies, the two DC power supplies are opened. When the DC electromagnetic contactor has a small current capacity, it can be safely opened without stopping the DC power supply device.

In the DC connection control device according to the third aspect of the present invention,
When connecting the two DC power supply units, the control unit turns on the DC electromagnetic contactor in response to an external connection command between the two DC power supply units. The DC power supply unit, which had been stopped when the DC electromagnetic contactor was turned on, was controlled by gradually increasing the base current of the charging transistor while conducting the connection control while monitoring it so that it did not exceed a certain value. A large current that is about to flow into the electrolytic capacitor from the activated DC power supply can be suppressed by the charging transistor, and the current can be controlled so that the current gradually flows into the stopped DC power supply side electrolytic capacitor. The two DC power supplies can be connected in parallel without stopping the activated DC power supply.

In the DC connection opening control device according to the fourth aspect of the present invention, when the two DC power supply devices are connected, a DC electromagnetic contactor is turned on in response to an external connection command between the two DC power supply devices, Thereafter, the DC electromagnetic contactor is turned on by performing a connection control for gradually increasing the base current of the charging transistor and conducting the current while monitoring the current detection value of the current detector so that it does not exceed a certain value. The charging transistor suppresses the large current from flowing into the electrolytic capacitor on the DC power supply that has been stopped until then from the DC power supply that has been activated, and the current gradually stops on the DC power supply. It is possible to control two DC power supply units without stopping the DC power supply unit that is running even with a small-capacity DC electromagnetic contactor. It can be connected to Parallel.

When the two DC power supplies are opened, the current detection value of the current detector is monitored in response to an open command between the two DC power supplies until it becomes equal to or less than a predetermined value. By gradually lowering the base current of the charging transistor and shutting it off, and then performing opening control to open the DC electromagnetic contactor, first gradually cut off the breaking current through the charging transistor, and after sufficiently reducing the DC current, Since the electromagnetic contactor is opened, a large breaking current does not flow at the time of opening, and even if current flows between the two DC power supplies, the breaking current flowing when opening between the two DC power supplies becomes small. Even a DC electromagnetic contactor having a small current capacity can be safely opened without stopping the DC power supply.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a circuit diagram of a common embodiment of the invention of the DC connection control device of the first embodiment and the invention of the DC connection release control device of the second embodiment.
In order to connect the DC converters 11 and 12 in parallel, a two-pole connection / disconnection electromagnetic contactor 13, a one-pole charging resistance short-circuiting electromagnetic contactor 14, and this charging resistance short-circuiting electromagnetic contactor 14 in parallel The charging resistor 15 provided, a voltage detector 16 for monitoring the voltage between both ends of the charging resistor 15, and a connection opening electromagnetic contactor 13 in response to a connection command 17 from the outside are turned on. When the voltage difference detected by the contact 16 becomes equal to or smaller than a predetermined value, the electromagnetic contactor 1 for short-circuiting the charging resistor 1
A control unit 18 for performing a connection control for turning on the power supply 4 and an opening control for opening the charging contact shorting electromagnetic contactor 14 in response to an external opening command 17 and then opening the connection opening electromagnetic contactor 13 It is composed of And each DC /
Electrolytic capacitors 19 and 20 are provided in the DC converters 11 and 12, respectively.

Description of the operation of the DC connection control device and the DC connection release control device having the above configuration << Connection Operation >> When the control unit 18 receives a connection command 17 from the outside, first, the connection release electromagnetic contactor 13 is turned on. I do.
At this time, for example, when the DC / DC converter 11 is being activated and the DC / DC converter 12 is being stopped, the charging current whose peak value is limited from the activated DC / DC converter 11 through the charging resistor 15 is being stopped. Flowing toward the DC / DC converter 12, the electrolytic capacitor 20 is charged (steps S1 and S1 in the flowchart of FIG. 2).
2).

The control unit 18 uses the voltage detector 16 to control both D
The voltage difference between the C / DC converters 11 and 12 is detected, and when the voltage falls below a predetermined value, the electromagnetic contactor 14 for short-circuiting the charging resistor.
Is input (steps S4 and S5).

With the above operation, regardless of whether the DC / DC converters 11 and 12 are being started or stopped, a DC circuit can be connected without flowing a large charging current to the electrolytic capacitor 19 or 20. Will be able to

<< Opening Operation >> When the control unit 18 receives an opening command 17 from the outside, first, the charging contact shorting electromagnetic contactor 14 is opened. As a result, both DC / DC converters 1
Even when a current flows between the terminals 1 and 12, the current flows through the charging resistor 15 and decreases (step S).
6, S7).

If the control unit 18 monitors the voltage detected by the voltage detector 16 and determines that the current has decreased to a predetermined value or less, the control unit 18 opens the connection opening electromagnetic contactor 13 (steps S8 to S10). ).

By controlling the opening by the control unit 18, the current is sufficiently small when the connection opening electromagnetic contactor 13 is opened, and the cutoff current is also small. Therefore, the connection opening electromagnetic contactor 13
Can operate safely even if the breaking current capacity is small, and the size of the entire device can be reduced.

Next, a description will be given of a common embodiment of the DC connection control device according to the third aspect of the invention and the DC connection release control device according to the fourth aspect of the invention with reference to FIG. In the embodiment of the DC connection control device and the DC connection release control device shown in FIG. 3, the same elements as those in FIG. 1 are denoted by the same reference numerals. , A charging transistor 21 is provided, and a current detector 22 is provided instead of the voltage detector 16.
Then, the control unit 23 receives the connection command 17 from the outside, turns on the connection opening electromagnetic contactor 13, and then monitors the current detection value of the current detector 22 so that it does not exceed a certain value. The connection control for gradually increasing the base current of the charging transistor 21 and conducting the connection, and receiving the opening command 17 from the outside, first reduce the base current of the charging transistor 21 while observing the detection current of the current detector 22. It has a function of turning off and then performing opening control for opening the connection opening electromagnetic contactor 13.

Next, the operation of the DC connection control device and the DC connection release control device configured as described above will be described.

<< Connection Operation >> When the control unit 23 receives a connection command 17 from outside, first, the connection release electromagnetic contactor 13
Input. In the early stage of this turning on, the charging transistor 2
In No. 1, no base current is given, and no current flows between the DC / DC converters 11 and 12 (steps S11 and S12 in the flowchart of FIG. 4).

However, after turning on the connection opening electromagnetic contactor 13 of the control unit 23, the base current of the charging transistor 21 is gradually increased while monitoring that the current detected by the current detector 22 does not exceed a predetermined value. Finally, a saturation current is applied (steps S13 and S1).
4).

Thus, also in this embodiment, a large charging current is supplied to the electrolytic capacitor 19 or 20 by the above operation regardless of whether the DC / DC converters 11 and 12 are being started or stopped. A DC circuit can be connected without flowing.

<< Opening Operation >> When the control section 23 receives an opening command 17 from the outside, first, the base current of the charging transistor 21 is gradually reduced while watching the detection current of the current detector 22 to be turned off. / DC converters 11 and 12
Even if currents are flowing between them, the currents are gradually reduced and cut off (steps S15 to S17).

Thereafter, the connection opening electromagnetic contactor 13 is opened to complete the opening operation (step S18).

Thus, also in the case of this embodiment, the control unit 2
By performing the opening control by 3, when the connection opening electromagnetic contactor 13 is opened, the current is sufficiently small, and the interruption current is also small. Therefore, the connection opening electromagnetic contactor 13 can be operated safely even if the breaking current capacity is small, and the size of the entire apparatus can be reduced.

In the case of the second embodiment, the charging resistor 15 used in the first embodiment can be omitted, and a contactless charging transistor 21 is used instead of the charging resistor short-circuiting electromagnetic contactor 14. As a result, maintenance can be reduced. In the case of the first embodiment, the charge resistance 1
5 and the charging contact short-circuiting electromagnetic contactor 14, the DC / DC converters 11, 1 are used when the load of both DC / DC converters 11, 12 is different.
A slight rush current may flow into the electrolytic capacitor at the moment when the charging resistor 15 is short-circuited, but in the case of the second embodiment, it is connected by the charging transistor 21. DC / DC converter 1
Because the impedance of 1,12 decreases linearly,
Inrush current to the electrolytic capacitor can be completely suppressed.

[0036]

According to the DC connection control device of the first aspect of the present invention, when connecting between two DC power supply devices, the control unit first receives a connection command between the two DC power supply devices from outside. The first direct current electromagnetic contactor is turned on, and when the voltage difference detected by the voltage difference detector falls below a predetermined value, the second direct current electromagnetic contactor is turned on.
Since the connection control for turning on the DC electromagnetic contactor of the first embodiment is performed, the DC power supply that has been activated until the electrolytic capacitor of the DC power supply unit that has been stopped when the first DC electromagnetic contactor is turned on is started. The large current that is about to flow from the device is suppressed by the charging resistor, and the current can be controlled so that the current gradually flows into the electrolytic capacitor on the side of the DC power supply that is stopped, and the DC power supply that is starting can be stopped. And two DC power supplies can be connected in parallel.

According to the DC connection opening control apparatus of the second aspect, in addition to the first aspect, when the two DC power supply apparatuses are opened, the opening between the two DC power supply apparatuses from the outside is further performed. In response to the command, the control unit first opens the second DC electromagnetic contactor, and thereafter performs opening control for opening the first DC electromagnetic contactor. Opening causes a breaking current to flow between the two DC power supplies through the charging resistor, and after sufficiently reducing the current, opens the first DC electromagnetic contactor, so that a large breaking current does not flow at the time of opening. Even when current flows between the two DC power supplies, the breaking current that flows when the two DC power supplies are opened can be reduced. Two DC power supplies are connected in parallel without stopping the DC power supply,
In addition, the DC power contact device can be opened and opened, and even if the DC electromagnetic contactor has a small capacity, it can be safely connected and opened without stopping the DC power supply device, and the entire device can be downsized.

According to the DC connection control device of the third aspect of the present invention, when the two DC power supply devices are connected, the control unit receives the connection command between the two DC power supply devices from the outside, and the control unit controls the DC electromagnetic contact. Since the power supply is turned on and the current detection value of the current detector is monitored so that it does not exceed a certain value, the connection control for gradually increasing the base current of the charging transistor and conducting the current is performed. When the DC electromagnetic contactor is turned on, the charging transistor suppresses the large current that is about to flow from the active DC power supply into the electrolytic capacitor on the DC power supply that had been stopped until then, and the current gradually decreases. It can be controlled so that it flows into the electrolytic capacitor on the side of the stopped DC power supply, and the two DC power supplies can be connected in parallel without stopping the activated DC power supply. It is possible.

According to the DC connection opening control apparatus of the fourth aspect, in addition to the third aspect, when the connection between the two DC power supply apparatuses is further opened, the external connection between the two DC power supply apparatuses is made external. While monitoring the current detection value of the current detector in response to the command, gradually lower the base current of the charging transistor until the current value becomes equal to or less than the predetermined value, cut off the current, and then perform the opening control of opening the DC electromagnetic contactor. Since the DC current is gradually reduced through the charging transistor, and the DC electromagnetic contactor is opened after the current is sufficiently reduced, a large interrupting current does not flow when the DC transistor is opened. Even when current flows between the two DC power supplies, the breaking current that flows when the two DC power supplies are opened can be reduced. Without stopping the DC power supply
Two DC power supplies can be connected in parallel and opened, and even with a DC current contactor with a small current capacity, it can be safely connected without stopping the DC power supply,
It can be opened, and the size of the entire device can be reduced.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a common embodiment of the first and second aspects of the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment.

FIG. 3 is a circuit diagram of a common embodiment of the inventions of claims 3 and 4;

FIG. 4 is a flowchart showing the operation of the embodiment.

FIG. 5 is a circuit diagram of a conventional example.

FIG. 6 is a circuit diagram of another conventional example.

[Explanation of symbols]

 11, 12 DC / DC converter 13 Electromagnetic contactor for connection opening 14 Electromagnetic contactor for charging resistance short circuit 15 Charging resistance 16 Voltage detector 17 Connection opening command 18 Control unit 19, 20 Electrolytic capacitor 21 Charging transistor 22 Current detector 23 Control unit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02J 1/12 H02J 1/00

Claims (4)

(57) [Claims] A first DC electromagnetic contactor having two or more poles for connecting and opening two DC power supply devices, and connecting between one of the DC power supply devices and the first DC electromagnetic contactor; A second DC electromagnetic contactor to be opened; and the second DC electromagnetic contactor provided in parallel with the second DC electromagnetic contactor.
A charging resistor for charging an electrolytic capacitor of each of the two DC power supply devices; a voltage difference detector for detecting a voltage difference between both sides of the second DC electromagnetic contactor; Receiving the connection command, turning on the first DC electromagnetic contactor, and then turning on the second DC electromagnetic contactor when the voltage difference detected by the voltage difference detector becomes a predetermined value or less. A DC connection control device comprising: a control unit for performing control. 2. A first DC electromagnetic contactor having two or more poles for connecting and opening two DC power supply devices, and connecting between one of the DC power supply devices and the first DC electromagnetic contactor, A second DC electromagnetic contactor to be opened; and the second DC electromagnetic contactor provided in parallel with the second DC electromagnetic contactor.
A charging resistor for charging an electrolytic capacitor of each of the two DC power supply devices; a voltage difference detector for detecting a voltage difference between both sides of the second DC electromagnetic contactor; Receiving the connection command, turning on the first DC electromagnetic contactor, and then turning on the second DC electromagnetic contactor when the voltage difference detected by the voltage difference detector becomes a predetermined value or less. Receiving the control and an open command between the two DC power supply devices from the outside, the second DC electromagnetic contactor is opened, and then the first DC electromagnetic contactor is opened.
And a control unit for performing an opening control for opening the DC electromagnetic contactor. 3. A DC electromagnetic contactor having two or more poles for connecting and opening between two DC power supply devices, and intermittent charging current flowing through respective electrolytic capacitors of the two DC power supply devices via the DC electromagnetic contactor. A charging transistor for controlling, a current detector for detecting a current flowing through the charging transistor, and receiving a connection command between the two DC power supply devices from the outside, turning on the DC electromagnetic contactor, A control unit for performing a connection control for gradually increasing the base current of the charging transistor and conducting the current while monitoring the current detection value of the current detector so that the current detection value does not exceed a predetermined value. apparatus. 4. A two-pole or more direct-current electromagnetic contactor for connecting and opening between two direct-current power supplies, and intermittent charging current flowing through each of the two direct-current power supply electrolytic capacitors via the direct-current electromagnetic contactor. A charging transistor for controlling, a current detector for detecting a current flowing through the charging transistor, and receiving a connection command between the two DC power supply devices from the outside, turning on the DC electromagnetic contactor, A connection control for gradually increasing the base current of the charging transistor to conduct while monitoring the current detection value of the current detector so that it does not exceed a certain value, and connecting the two DC power supply devices from the outside. While monitoring the current detection value of the current detector in response to the release command of the above, the base current of the charging transistor is gradually lowered until the current value becomes equal to or less than a predetermined value, and the current is turned off. And a controller for performing an opening control for opening the DC electromagnetic contactor, and thereafter, a DC connection opening control device.