JP5003541B2 - Power supply device and control method thereof - Google Patents

Description

  The present invention relates to a power supply device and a control method therefor, and more particularly to a power supply device capable of hot-line insertion and a control method for such a power supply device.

  There is a power supply device that can be hot-plugged in a power supply line that supplies power to a load from the power supply device. At the time of hot line insertion, if the power supply device to be hot inserted is inserted into the power supply line as it is, current flows from the existing operation power supply device to the newly inserted power supply device. Usually, in order to prevent this inflow, the power supply device has a semiconductor element (a diode or a transistor) for preventing a current inflow, which is inserted in series with the power output terminal.

  Regarding prevention of current flow, Patent Document 1 describes a circuit that suppresses an inrush current flowing through a capacitive load when a power supply is connected. In Patent Document 1, the circuit includes a transistor inserted in series with a capacitive load between power supply lines. In Patent Document 1, an inrush current is suppressed by changing a gate voltage of a transistor by a time constant change voltage by a time constant circuit and controlling a current flowing through the transistor.

Patent Document 2 describes an inrush current prevention circuit that suppresses an inrush current when hot-inserting an electronic circuit into a power supply line. FIG. 6 shows an inrush current prevention circuit described in Patent Document 2. The power supply circuit and the electronic circuit are connected by a power supply side connector Cp and an electronic circuit side connector Cc. Connector Cp includes a power supply terminal Tv1, Tv2 connected to the Vcc power source line, the connected power terminal _{T E} to the GND line. The connector Cc has power input terminals Te, Tc, and Tb. The length of the pin of the power input terminal Te is longer than the length of the pin of the power input terminal Tc.

During live insertion, are connected with a connector Cp and the connector Cc, the power supply terminal Tv2 and the power input terminal Te, and a power supply terminal T _E and the power input terminal Tb is connected. At this time, since the pin length of the power input terminal Tc is shorter than the pin length of the power input terminal Te, the power input terminal Tc is connected to the power terminal Tv1 of the connector Cp later than the other terminals. Power is supplied from the power input terminal Te until the power input terminal Tc is connected to the power terminal Tv1. A transistor Tr is inserted between the power input terminal Te and the electronic circuit, and an inrush current is prevented by the transistor Tr. Thereafter, when the power input terminal Tc is connected to the power terminal Tv1, the emitter and collector of the transistor Tr are short-circuited. For this reason, the electronic circuit is supplied with power in a steady state from the power input terminal Tc.

JP 2004-129419 A JP-A-8-317556

  In Patent Document 1, an inrush current preventing transistor is inserted in series with a load between power supply lines. Since the transistor generates a loss even in the ON state, the transistor causes a loss at the steady state. In particular, when the current flowing through the load is increased, the loss due to the transistor cannot be ignored and the power supply efficiency is lowered. In Patent Document 2, immediately after the hot line is inserted, the power input terminal Tc is connected with a delay from the power input terminal Te, thereby suppressing an inrush current and avoiding a decrease in power efficiency due to the loss of the transistor Tr. However, in Patent Document 2, since power is supplied by two systems, there arises a problem that a current system through which a large current flows is separately required for the connector.

  An object of this invention is to provide the power supply device which can suppress the inflow current at the time of hot insertion, and its control method, without requiring the electric current system into which a big electric current flows separately.

  In order to achieve the above object, a power supply device of the present invention is a power supply device that can be hot-wired to a power supply line that is supplied with power by another power supply device, and is connected between output power supply lines. An inflow current suppression unit that is connected in series with the output power stabilization capacitor and the output power supply line, in series with the power supply output stabilization capacitor, and suppresses a charging current that flows from another power supply device into the power output stabilization capacitor. And a current control unit that controls a charging current that is suppressed by the flowing-in current suppression unit when a hot wire is inserted into the power supply device.

  The method for controlling a power supply apparatus according to the present invention includes a power supply output stabilization capacitor connected between output power supply lines, and a power supply apparatus that can be hot-wired to a power supply line that is supplied with power by another power supply apparatus And when the power supply device is hot-plugged, the power supply output stabilization capacitor is connected in series between the output power supply lines, and the power supply output stabilization capacitor is connected to another power supply device. The charging current that is suppressed by the flowing-in current suppressing unit that suppresses the charging current that flows in is gradually increased.

  The power supply device and the control method thereof according to the present invention can suppress a flowing-in current at the time of hot-line insertion without requiring a current system through which a large current flows separately.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a power supply device according to a first embodiment of the present invention. The power supply apparatuses 10-1 to 10-3 are separate apparatuses having the same function that can be operated in parallel. The power supply apparatuses 10-1 to 10-3 supply power to the load 40 through a common output power supply line. Each power supply device can be hot-wired to the output power supply line. For example, when the power supply device 10-1 (power supply device A) and the power supply device 10-2 (power supply device B) are already supplying power to the load 40, the power supply device 10-3 (power supply device C). Can be hot-plugged into the output power line, and power can be supplied by a total of three power supply devices.

  FIG. 2 shows the configuration of the power supply device. The power supply device (power supply device A) 10 includes a power supply smoothing unit 11 and a power supply control unit 12, an inflow current suppression unit 21, a charge detection unit 22, and a current control unit 23. Although not shown in FIG. 2, the other power supply apparatuses B to D have the same configuration as that of the power supply apparatus A. The power supply devices A to D are connected to each other via the connection board 30 and supply power to the load 40 (FIG. 1) via the connection board 30. The power supply smoothing unit 11 is connected to the plus side output terminal XA and the minus side output terminal YB, and generates power to be supplied to the load. The power control unit 12 controls power generation by the power smoothing unit 11.

  The positive output terminals XA to XD and the negative output terminals YA to YD of each power supply device are connected to each other in the connection board 30. The connection terminals ZA to ZD are connected to each other in the connection board 30. The wiring connecting the connection terminals ZA to ZD is grounded in the connection board 30. The connection board 30 and each power supply device are connected by a connector. The pin lengths of the connection terminals ZA to ZD are shorter than the pin lengths of the output terminals XA to XD and the output terminals YA to YD. Since the connection terminals ZA to ZD have short pins, they are connected to the terminals on the connection board side after the output terminals XA to XD and the output terminals YA to YD when the connectors are inserted.

  The power supply output stabilizing capacitor C1 is connected between the positive output terminal XA and the negative output terminal YA, that is, between the output power supply lines. The inflow current suppression unit 21 is connected in series with the capacitor C1 between the output power supply lines. The flowing-in current suppressing unit 21 suppresses current flowing into the power supply device from the output terminals XA and YA when the power supply device 10 is hot-lined. The inflow current suppression unit 21 includes a transistor Q1. The current control unit 23 controls the charging current of the capacitor C <b> 1 that the inflow current suppression unit 21 suppresses. The current control unit 23 controls the flowing-in current suppressing unit 21 so as to gradually increase the charging current of the capacitor C1 after the hot line is inserted.

  The current control unit 23 includes a comparator Z1, resistors R1 and R2, and a capacitor (control capacitor) C2. The comparator Z1 has a negative input terminal connected to the connect terminal ZA and a positive input terminal connected to the reference voltage V1. The comparator Z1 compares the reference voltage V1 with the voltage at the connection terminal ZA. The output of the comparator Z1 is connected to the connection point of the resistors R1 and R2 that are directly connected between the internal voltage VCC and the ground voltage. The capacitor C2 is connected in parallel with the resistor R2 between the output of the comparator Z1 and the ground voltage. The output of the comparator Z1 is connected to the gate of the transistor Q1 of the inflow current suppression unit 21. The current control unit 23 controls the inflow current suppression unit 21 based on the output of the comparator Z1.

  The voltage of the connection terminal ZA is pulled up to the internal voltage VCC via the resistor R5 when not connected to the connection board 30. The reference voltage V1 is a voltage lower than the internal voltage VCC. The comparator Z1 sets the output to the ground voltage level because the voltage at the connect terminal ZA is higher than the reference voltage V1 when the connect terminal ZA is not connected to the connection board 30. In this case, the gate voltage of the transistor Q1 is the ground voltage, and the transistor Q1 is turned off.

  When the connector is connected and the connect terminal ZA is connected to a terminal in the connection board, the voltage of the connect terminal ZA drops to the ground voltage. The comparator Z1 sets the output to OPEN when the voltage at the connection terminal ZA becomes lower than the reference voltage V1. When the output of the comparator Z1 becomes OPEN, the voltage of the capacitor C2 rises to a voltage obtained by dividing the internal voltage Vcc by the resistors R1 and R2 with a time constant by the resistors R1 and R2 and the capacitor C2. In the transistor Q1, the output voltage of the comparator Z1, that is, the voltage of the capacitor C2, increases, the impedance decreases, and the transistor Q1 shifts to the ON state.

  The charge detection unit 22 detects the charging of the capacitor C1 for stabilizing the power output. The charge detection unit 22 includes a comparator Z2. Resistors R3 and R4 are used to detect the charging voltage of the capacitor C1. The resistors R3 and R4 are connected in series between a connection node (the drain of the transistor Q1) between the capacitor C1 and the transistor Q1 and the negative output terminal YA. The reference voltage V2 is connected to the positive input terminal of the comparator Z2, and the negative input terminal is connected to the connection point of the resistors R3 and R4. The output of the comparator Z2 is pulled up to the internal voltage VCC via the resistor R6.

  When the output terminals XA and YA are connected to the connection board 30 at the time of hot line insertion, the voltage Vo generated by another power supply device appears at the output terminals XA and YA. At this time, in a state before the charging of the capacitor C1 is started, the voltage of the capacitor C1 is substantially 0, and the voltage between the source and the drain of the transistor Q1 is substantially equal to the voltage Vo. The voltage at the connection point between the resistor R3 and the resistor R4 is a voltage obtained by dividing the source-drain voltage of the transistor Q1 by the resistor R3 and the resistor R4. The reference voltage V2 is set lower than this divided voltage. In this state, the output of the comparator Z2 is at the ground potential level.

  When the capacitor C1 is charged and the voltage of the capacitor C1 becomes sufficiently high, the voltage at the connection point between the resistor R3 and the resistor R4 becomes lower than the reference voltage V2. The comparator Z1 changes the output to OPEN when the voltage at the connection point between the resistor R3 and the resistor R4 becomes lower than the reference voltage V2. Since the output of the comparator Z2 is pulled up by the resistor R6, the output of the comparator Z2 changes to the HIGH level (VCC level). That is, when the capacitor C1 is sufficiently charged, the output of the charge detection unit 22 changes from the LOW level to the HIGH level.

  The AND circuit Z4 takes a logical product of the output of the charge detection unit 22 and the output of the NOT circuit Z3 that inverts the voltage at the connection terminal ZA. The output of the AND circuit Z4 is HIGH when the connect terminal ZA is connected to the connect terminal of another power supply device via the connection board 30 and the charge detection unit 22 detects that the capacitor C1 is sufficiently charged. Is output. When the output of the AND circuit Z4 changes from the LOW level to the HIGH level, the power supply control unit 12 instructs the power supply smoothing unit 11 to start power supply.

  FIG. 3 shows operation waveforms of each part. It is assumed that the power supply devices B to D are already connected to the connection board 30 and the power supply by these power supply devices has already been performed. When the power supply device A10 is hot-connected to the connection board 30 at time T0, the voltage Vo output from the other power supply device appears at the output terminals XA and YA of the power supply device A10. At this time, the connection terminal ZA is not yet connected to the terminal in the connection board 30 because the length of the terminal is shorter than the output terminals XA and YA. In the current control unit 23, since the negative input terminal of the comparator Z1 is higher than the reference voltage V1, the output of the comparator Z1 is at the ground voltage level. Therefore, transistor Q1 is in a non-conductive state. Since the transistor Q1 is non-conductive, the charging current to the capacitor C1 is limited by the resistors R3 and R4, and the source-drain voltage VDS of the transistor Q1 substantially matches the voltage Vo (a).

  When the connection terminal ZA is connected to the connection board 30 at time T1 slightly after time T0, and the voltage at the connection terminal ZA decreases, the comparator Z1 detects when the voltage at the connection terminal ZA becomes lower than the reference voltage V1. , Change the output to OPEN. When the output of the comparator Z1 becomes OPEN, charging of the capacitor C2 starts. The voltage of the output of the comparator Z1 is divided by the resistors R1 and R2 according to the time constants of the resistors R1, R2 and the capacitor C2. It rises to the pressed voltage value. As the voltage rises, the source-drain conduction resistance value of the transistor Q1 gradually decreases, and the source-drain voltage VDS of the transistor Q1 gradually decreases (a). In synchronization with this decrease, the charging current to the capacitor C1 increases and the voltage VC1 of the capacitor C1 increases (b).

  When the source-drain voltage VDS of the transistor Q1 decreases, the voltage VR4 at the connection point between the resistor R3 and the resistor R4 connected in parallel with the transistor Q1 also decreases. When the voltage VR4 becomes lower than the reference voltage V2 input to the plus side input terminal of the comparator Z2 at time T2, the output of the comparator Z2 becomes OPEN and changes to the HIGH level. The output of the NOT circuit Z3 changes to HIGH level after the connection terminal ZA is connected to the terminal in the connection board 30 at time T1. For this reason, the output of the AND circuit Z4 changes to HIGH level when the output of the comparator Z2 changes to HIGH level at time T2 (c). When the output of the AND circuit Z4 becomes HIGH level, the power supply control unit 12 instructs the power supply smoothing unit 11 to start power supply. By such an operation, the charging current of the capacitor C1 is gradually increased from the time when the power supply device is hot-plugged, and the power supply can be started after the charging is completed.

  In the present embodiment, the flowing-in current suppressing unit 21 is connected in series with the capacitor C1 between the output power supply lines. After the hot wire is inserted, the current controller 23 controls the inflow current suppressor 21 so as to gradually increase the charging current of the capacitor C1. By doing in this way, the electric current which flows into the capacitor | condenser C1 from another power supply device at the time of hot-line insertion can be suppressed. The connect terminal is a terminal for recognizing that it is connected to another power supply apparatus, and is not a terminal through which a large current flows. Therefore, in this embodiment, it is possible to suppress the flowing-in current at the time of hot-line insertion without requiring a current system through which a large current flows separately.

  In the present embodiment, since the flowing-in current suppressing unit 21 is connected in parallel to the output terminal, the output current of the power supply smoothing unit 11 flows into the flowing-in current suppressing unit 21 in a normal use state after inserting a hot wire. There is no flow. Therefore, it is possible to reduce the loss caused by the flowing-in current suppressing unit 21 in a normal use state while suppressing the flowing-in current at the time of hot line insertion, and it is possible to increase the power supply efficiency. Further, considering the case where the power supply device is activated (steady activation) with the power supply device connected to the connection board instead of hot-plugging, the transistor Q1 of the flowing-in current suppression unit 21 is already in a conductive state. Therefore, at the time of steady startup, the charging current of the capacitor C1 is not suppressed by the flowing-in current suppression unit, and the power supply device can be started up with a power supply startup time equivalent to that of a normal power supply device.

  FIG. 4 shows a power supply device according to a second embodiment of the present invention. This embodiment is different from the first embodiment in that the charging voltage of the capacitor C1 for stabilizing the power output is detected based on the voltage across the resistor R3. The charge detection unit 22a includes resistors R7 to R10 and a comparator Z5 that constitute a differential amplifier, and a comparator Z6 that compares the output voltage of the differential amplifier (comparator Z5) with a reference voltage V3. The differential amplifier in the charge detection unit 22a amplifies the voltage across the resistor R3 at a predetermined magnification.

  After the connection terminal ZA is connected, the operation in which the inflow current suppression unit 21 gradually increases the charging current by the current control unit 23 is the same as the operation in the first embodiment. When charging of the capacitor C1 proceeds and the voltage across the resistor R3 is sufficiently reduced, the output of the comparator Z5 becomes lower than the reference voltage V3. The comparator Z6 changes the output to the HIGH level when the output of the comparator Z5 becomes lower than the reference voltage V3. In FIG. 4, the output of the charge detection unit 22a (comparator Z6) is directly input to the power supply control unit 12, but the logical product of the output of the comparator Z6 and the inverted voltage of the connection terminal ZA is obtained. The charging detection unit 22a may be input.

  FIG. 5 shows operation waveforms of each part. It is assumed that the power supply devices B to D are already connected to the connection board 30 and the power supply by these power supply devices has already been performed. When the power supply device A10 is hot-connected to the connection board 30 at time T0, the voltage Vo output from the other power supply device appears at the output terminals XA and YA of the power supply device A10. At time T0, the connection terminal ZA is not connected to the connection board, the output of the comparator Z1 is at the installation potential level, and the transistor Q1 is in a non-conductive state. Therefore, the source-drain voltage VDS of the transistor Q1 substantially matches the voltage Vo (a).

  When the connection terminal ZA is connected to the connection board 30 at time T1, the output voltage of the comparator Z1 gradually increases from that point, the conduction resistance of the transistor decreases, and the source-drain voltage VDS of the transistor Q1. Gradually decreases (a). Along with this, the voltage VC1 of the capacitor C1 increases (b). The operations up to here are the same as in the first embodiment.

  When the source-drain voltage VDS of the transistor Q1 decreases, the voltage obtained by dividing the source-drain voltage VDS by the resistors R3 and R4 also decreases, and the voltage across the resistor R3 decreases. When the output voltage of the differential amplifier that amplifies the voltage across the resistor R3 becomes lower than the reference voltage V3 input to the plus side input terminal of the comparator Z6 at time T2, the output of the comparator Z6 changes to HIGH level. (C). When the output of the comparator Z6 becomes HIGH level, the power control unit 12 instructs the power smoothing unit 11 to start power supply. By such an operation, the charging current of the capacitor C1 is gradually increased from the time when the power supply device is hot-plugged, and the power supply can be started after the charging is completed.

  In the present embodiment, the charge voltage of the capacitor C1 is detected using a differential amplifier for the charge detector 22a. Even with such a configuration, the same effect as the first embodiment can be obtained. In the first embodiment and the second embodiment, the divided voltage by two resistors connected in series is used for detecting the charging voltage of the capacitor C1, but the charging voltage is detected using a single resistor. Configuration is also possible.

  Although the present invention has been described based on the preferred embodiment, the power supply apparatus and the control method of the present invention are not limited to the above embodiment, and various modifications and changes can be made to the configuration of the above embodiment. Changes are also included in the scope of the present invention.

The block diagram which shows the state which supplies power to load with a several power supply device. The block diagram which shows the power supply device of 1st Embodiment of this invention. The wave form diagram which shows the operation | movement waveform of each part. The block diagram which shows the power supply device of 2nd Embodiment of this invention. The wave form diagram which shows the operation | movement waveform of each part in the power supply device of 2nd Embodiment. FIG. 9 is a block diagram showing a circuit described in Patent Document 2.

Explanation of symbols

10: Power supply device 11: Power supply smoothing unit 12: Power supply control unit 21: Inflow current suppression unit 22: Charge detection unit 23: Current control unit

Claims (9)

A power supply device that can be hot-wired to a power supply line that is powered by another power supply device,
A power output stabilization capacitor connected between the output power lines;
A flow-in current suppression unit that is connected in series with the power supply output stabilization capacitor between the output power supply lines and suppresses a charging current that flows from another power supply device into the power supply output stabilization capacitor;
A power supply device comprising: a current control unit that controls a charging current that is suppressed by the flowing-in current suppressing unit when a hot wire is inserted in the power supply device.   The power supply device according to claim 1, wherein the current control unit gradually increases the charging current after inserting a hot wire.   The flow-in current suppression unit includes a transistor connected in series with the power supply output stabilization capacitor, and the current control unit gradually reduces the conduction resistance of the transistor after being connected to the live line. 2. The power supply device according to 2.   The current control unit starts control of the charging current when a connect terminal for detecting connection with another power supply device is connected with another power supply device. The power supply described.   The power supply according to claim 4, wherein the connection terminal is connected to a connection terminal of another power supply device after a power supply output terminal connected to the output power supply line is connected to a power supply output terminal of another power supply device. apparatus.   The current control unit includes a comparator that compares the connection terminal with a reference voltage, a first resistor connected between the output of the comparator and a predetermined internal voltage, and the output of the comparator and the ground voltage. A second resistor connected in between, and a control capacitor connected in parallel with the second resistor between the output of the comparator and the installation voltage, and the inflow current suppression unit includes an output of the comparator The power supply device according to claim 4, wherein the charging current is controlled based on the power supply.   The connection terminal is held at a voltage higher than the reference voltage before connection to the connection terminal of another power supply apparatus, and is held at a voltage lower than the reference voltage after connection to the connection terminal of another power supply apparatus. The power supply according to claim 6, wherein the comparator holds the output at a ground voltage level when the voltage at the connection terminal is higher than the reference voltage, and sets the output to the OPEN state when the voltage is lower than the reference voltage. apparatus. A charge detector for detecting a charging voltage of the power stabilization capacitor;
When the charge detection unit detects that the charging voltage of the capacitor has reached a predetermined voltage, the power supply smoothing unit for generating power further includes a power supply control unit for instructing start of power supply to the output power supply line. Item 8. The power supply device according to any one of Items 1 to 7. A control method of a power supply device having a power output stabilization capacitor connected between output power supply lines and capable of being hot-wired to a power supply line that is supplied with power by another power supply device,
When hot plugging the power supply device, the power supply output stabilization capacitor is connected in series between the output power supply lines, and the charging current flowing from the other power supply device to the power supply output stabilization capacitor is suppressed. A control method for a power supply device that gradually increases a charging current suppressed by a flowing-in current suppressing unit.

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