JP2012244745A - Power unit and control voltage generation unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power unit whose reliability is higher than that of a conventional power unit.SOLUTION: In a power unit 1, one of control voltage generation units 5-1 to 5-n is provided one for one DC-DC converter, in which a first current generation unit 4 generates control even voltage Vr for controlling current to be output by the respective DC-DC converters by evenly dividing potential difference between an output part 4b which outputs current Ir and a termination unit 6 which establishes potential of the output part 4b for every DC-DC converter.

Description

  The present invention relates to a power supply device including a plurality of DC-DC converters and a control voltage generation unit.

  As a power supply device that is a device for supplying desired power to a load, a power supply device using a DC-DC converter (DC-DC converter) or the like has been conventionally used.

  Here, a case is considered in which the desired power supplied to the load is large, so that one power supply device cannot supply the desired power to the load. The fact that the desired power supplied to the load is large means that the load current that is the current flowing to the load is large.

  In this case, in the power supply device, a plurality of power supply devices are connected in parallel. Thereby, desired power required by the load can be supplied from a plurality of power supply devices.

  Patent Document 1 discloses a power supply device that connects a plurality of power supply devices in parallel. In the power supply device of Patent Document 1, a plurality of DC-DC converters including differential amplifiers are connected in parallel. Further, the non-inverting input terminal (+) of each differential amplifier is connected in parallel to the current common bus (that is, connected in common).

  In the above configuration, the maximum current value in the current common bus is compared with the maximum current value indicating the result of detecting the output current in each differential amplifier. And based on the comparison result, the frequency of the signal input into the gate of the switching element with which each DC-DC converter is provided is controlled (switching control).

  The potential in the current common bus is a maximum potential that is a potential corresponding to the maximum current output from the DC-DC converter having the maximum output current among the plurality of DC-DC converters. In other DC-DC converters, control is performed so that the current output from the DC-DC converter follows the maximum current based on the maximum potential.

JP 2006-262651 A (published on September 28, 2006)

  In the power supply device of Patent Document 1, in a plurality of DC-DC converters connected in parallel, the output current of each DC-DC converter follows the maximum current, and the output current of each DC-DC converter is It reaches equilibrium.

  For this reason, output current variation (value difference) occurs among the plurality of DC-DC converters until the output current of each DC-DC converter reaches equilibrium.

  Further, the required power of the load varies depending on the operating state of the load. Thereby, the electric power supplied from each DC-DC converter to a load fluctuates. Therefore, the output current of each DC-DC converter varies. Thereby, the maximum current fluctuates. Since the output current of each DC-DC converter follows the maximum current, variation is likely to occur in the current supplied to the load by each DC-DC converter.

  Regarding the reliability of the power supply device, when only one DC-DC converter among the plurality of DC-DC converters has an output current larger than that of others (variation occurs), the one DC-DC converter Only the converter is hotter than the others. In this case, only the parts constituting the one DC-DC converter have a higher temperature than the others, and the reliability as a power supply device is impaired. Specifically, the service life is shortened or the probability of failure is increased.

  In addition, when variation occurs in the current supplied to each load by each DC-DC converter, abnormal noise may occur in a transformer included in the DC-DC converter.

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide a power supply device having higher reliability than a conventional power supply device.

  In order to solve the above problems, the power supply device of the present invention has at least two DC-DC converters connected in parallel to the load, and each DC-DC converter supplies power to the load. A power supply device that supplies electric power, and a first current generation unit that generates a first current corresponding to a load current that is a current flowing through the load, and one power supply device are provided for one DC-DC converter. The potential difference between the output section from which the first current generating section outputs the first current and the termination section for determining the potential of the output section is proportional to the capability of each DC-DC converter. A control voltage generation unit that generates a control voltage for controlling a current output from each DC-DC converter by dividing each DC converter is provided.

  According to the above invention, the control voltage for controlling the current output from each DC-DC converter is generated in each control voltage generator.

  The control voltage is the potential difference between the output unit and the termination unit, and the capability of each DC-DC converter (the maximum value of power that each DC-DC converter can output (ie, the maximum value of current)). In proportion to each DC-DC converter. When the capabilities of the DC-DC converters are the same, the control voltages are the same.

  A control voltage proportional to the capability of each DC-DC converter is input to each DC-DC converter. Thereby, the direct current, which is a current output from each DC-DC converter, becomes a current according to the capability of the DC-DC converter. Therefore, each DC-DC converter shares the load in proportion to its capacity, so that each DC-DC converter can achieve thermal equilibrium. In addition, when the capacity | capacitance of each DC-DC converter is the same, since it will bear a load equally, the temperature of each DC-DC converter becomes mutually equal.

  Regarding the reliability of the power supply device, if only one DC-DC converter among a plurality of DC-DC converters is burdened more than the capacity, or if the capacity is the same, the output current will be larger than the others. Only the one DC-DC converter has a higher temperature than the others. In this case, only the parts constituting the one DC-DC converter have a higher temperature than the others, and the reliability as a power supply device is impaired. Specifically, the service life is shortened or the probability of failure is increased.

  However, in the power supply device of the present invention, the direct current that is the current output from each DC-DC converter is a current according to the capability of each DC-DC converter. Therefore, the ratio of the load applied to a specific DC-DC converter does not become larger than the ratio of the load applied to another DC-DC converter. Therefore, higher reliability than the conventional power supply device can be obtained.

  Furthermore, the lifetime of the DC-DC converter varies depending on its own temperature, but since the temperature of each DC-DC converter is equal, the lifetime of each DC-DC converter is also equal. As a result, higher reliability than the conventional power supply device can be obtained.

  In the power supply device, the control voltage generator includes a shunt resistor having a resistance value proportional to the capability of the corresponding DC-DC converter, and the shunt resistor provided in each control voltage generator includes the output unit and the shunt resistor. You may connect in series between the said termination | terminus parts.

  Thereby, the divided control voltage can be generated according to the value of the shunt resistor. And when the capability of each DC-DC converter is the same, a shunt resistance can be set to the same resistance value, and the control voltage equally divided | segmented can be produced | generated.

  In the power supply apparatus, the DC-DC converter includes a second current generation unit that generates a second current corresponding to a direct current output by the DC-DC converter, and a target that is a target value of the direct current according to the control voltage. You may further provide the electric current target value setting part which produces | generates an electric current, and the comparison part which compares the said 2nd electric current and the said target electric current.

  Thus, the direct current that is the current output from each DC-DC converter is controlled according to the comparison result between the second current and the target current, and becomes a current according to the capability of the DC-DC converter. .

  In any one of the above power supply devices, the maximum value of the current that can be output by each DC-DC converter is the same, and the resistance values of the respective shunt resistors may all be equal.

  This makes it possible to generate a control voltage that is evenly divided.

  In any one of the above power supply devices, the maximum value of the current that can be output by each DC-DC converter is different, and the resistance value of each shunt resistor can be output by the corresponding DC-DC converter. It may be proportional to the maximum value of the current.

  Thereby, the resistance value of the shunt resistor becomes the resistance value of the shunt resistor according to the capability of each DC-DC converter, and the target current also becomes the value according to the capability of each DC-DC converter.

  For example, the resistance value of the shunt resistor of the control voltage generation unit corresponding to the DC-DC converter whose unit of capability is 1 is 1. At this time, the resistance value of the shunt resistor of the control voltage generation unit corresponding to the DC-DC converter whose capacity unit is twice is set to twice the resistance value of the shunt resistor whose resistance value is 1.

  Similarly, the resistance value of the shunt resistor of the control voltage generation unit corresponding to the DC-DC converter whose capacity unit is n times is assumed to be n times the resistance value of the shunt resistor whose resistance value is 1.

  By setting it as such a structure, the electric current target value of the magnitude | size according to each capability can be input into each DC-DC converter. As a result, each DC-DC converter can output a current corresponding to its own capacity, so that the ratio of the load to the capacity can be made constant.

  Therefore, the temperature of a specific DC-DC converter does not become higher than other DC-DC converters. Therefore, higher reliability than the conventional power supply device can be obtained.

  In any one of the above power supply devices, the control voltage generation unit includes a relay circuit and includes an inductor that operates the relay circuit, and a voltage output from a corresponding DC-DC converter is applied to the inductor, and the corresponding If the DC-DC converter has not failed, a voltage is applied from the DC-DC converter to the inductor, and the first current is caused to flow through the shunt resistor, thereby controlling the DC current. If a certain control voltage is generated and output to the DC-DC converter, and the DC-DC converter fails, no voltage is applied from the DC-DC converter to the inductor, and the shunt resistor is Since the first current is not passed, the control voltage may not be generated.

  When the connected DC-DC converter is not operating due to a failure or the like, the relay circuit included in the control voltage generator does not work. Therefore, the first current bypasses the shunt resistor (does not flow through the shunt resistor). For this reason, the resistance value of the shunt resistor included in the control voltage generation unit corresponding to the DC-DC converter that is not operating is not added to the closed circuit through which the first current flows. Therefore, it is possible to realize a power supply apparatus that generates the accurate control voltage with a simple configuration, excluding the inoperative DC-DC converter.

  In order to solve the above-described problem, the control voltage generation unit of the present invention includes at least two DC-DC converters connected in parallel to the load, and each DC-DC converter supplies power to the load. Is mounted on a power supply device including a first current generation unit that generates a first current corresponding to a load current that is a current flowing through the load, and for one DC-DC converter. A control voltage generating unit provided with a shunt resistor having a resistance value proportional to the capability of the corresponding DC-DC converter, and the first current flows through the shunt resistor. A switch between an on state that generates a control voltage for controlling the output of the DC converter and an off state in which the first current does not flow through the shunt resistor And a relay circuit for switching the road, the relay circuit, in conjunction with the operation of the DC-DC converter to the corresponding, characterized by turning on the switch circuit.

  According to the invention, the relay circuit turns on the switch circuit in conjunction with the operation of the corresponding DC-DC converter.

  Thereby, when the corresponding DC-DC converter has not failed, a control voltage proportional to the capability of each DC-DC converter can be output to the corresponding DC-DC converter.

  Therefore, since each DC-DC converter bears a load equally, the temperature of each DC-DC converter becomes equal to each other, and the temperature of a specific DC-DC converter is higher than that of other DC-DC converters. It wo n’t be expensive.

  Therefore, the control voltage generation unit of the present invention can provide a power supply device having higher reliability than the conventional power supply device.

  There is an effect of providing a power supply device having higher reliability than the conventional power supply device.

1 is a block diagram of a power supply device according to an embodiment of the present invention. 1 is a circuit diagram of a DC-DC converter according to an embodiment of the present invention. It is a circuit diagram of a control voltage generation unit according to an embodiment of the present invention. It is explanatory drawing for demonstrating how an electric current flows in the power supply device which concerns on embodiment of this invention. It is a block diagram of the power supply device which concerns on other embodiment of this invention. FIG. 6 is a circuit diagram of a control voltage generation unit according to another embodiment of the present invention.

  An embodiment of the present invention will be described below with reference to FIGS. First, an embodiment of the present invention will be described with reference to FIG.

Embodiment 1
An embodiment of the present invention will be described with reference to FIGS.

(Configuration of power supply device 1)
FIG. 1 is a block diagram of a power supply device 1 according to the first embodiment. The power supply device 1 includes a power supply 2, a DC-DC converter (DC-DC converter) 3-1 to 3-n, and a backflow prevention diode D- 1 corresponding to the DC-DC converter 3-1 to 3-n. R1 to D-Rn are provided. Further, the power supply device 1 includes control voltage generation units 5-1 to 5-n that correspond one-to-one with the first current generation unit 4 (first current generation unit) and the DC-DC converters 3-1 to 3-n. (Control voltage generation unit) and termination unit 6 (termination unit).

  Further, there are at least two DC-DC converters 3-1 to 3 -n, and in the case of the first embodiment, the capabilities of the DC-DC converters 3-1 to 3-n are the same. That is, the maximum value of electric power that can be output by the DC-DC converters 3-1 to 3-n (that is, the maximum value of current, which is called the capability of the DC-DC converter) is the same.

  Note that there is a limit (limit) on the capacity of each DC-DC converter 3-1 to 3-n. Therefore, a load current Itotal (described later) is caused to flow to the load 7 using a plurality of units.

  Further, the backflow prevention diodes D-R1 to D-Rn are diodes for preventing a current from flowing back from the load 7 to the DC-DC converters 3-1 to 3-n.

  Furthermore, the first current generation unit 4 can be rephrased as a load current measurement unit, and includes a detection unit 4a and an output unit 4b. The first current generation unit 4 will be described later with reference to FIG.

  In the first embodiment, “n” included in the sign means an integer of 2 or more. In the power supply device 1 of FIG. 1, four DC-DC converters and four control voltage generation units are shown. However, the power supply device 1 of FIG. 1 can be configured to include two DC-DC converters and two control voltage generation units. In this case, n = 2.

  In the power supply device 1 of FIG. 1, the output of the power supply 2 is connected to the inputs of DC-DC converters 3-1 to 3-n. The ground of the power supply 2 is connected to the first ground of the DC-DC converters 3-1 to 3-n.

  The output of the DC-DC converter 3-1 is connected to the anode of the backflow prevention diode D-R1. The outputs of the DC-DC converters 3-2 to 3-n are configured similarly to the output of the DC-DC converter 3-1. That is, the outputs of the DC-DC converters 3-2 to 3 -n are connected to the anodes of the backflow prevention diodes D-R 2 to D-Rn, respectively.

  The cathodes of the backflow prevention diodes D-R1 to D-Rn are each connected to the node N1. The node N1 is connected to one end of the detection unit 4a of the first current generation unit 4. The other end of the detection unit 4 a of the first current generation unit 4 is connected to one end of the load 7.

  The other end of the load 7 is connected to the node N2. The node N2 is connected to a second ground that each of the DC-DC converters 3-1 to 3-n has.

  The output unit 4b of the first current generation unit 4 is connected to the male connector of the control voltage generation unit 5-1. The female connector of the control voltage generation unit 5-1 is connected to the male connector of the control voltage generation unit 5-2. Similarly, the female connector of the control voltage generation unit 5- (n-1) is connected to the male connector of the control voltage generation unit 5-n. The female connector of the control voltage generation unit 5-n is connected to the termination unit 6.

  An output connector of the control voltage generation unit 5-1 is connected to an input of a current target value setting circuit 16-1 (see FIG. 2) provided in the DC-DC converter 3-1. The connection destination of the output connectors of the control voltage generation units 5-2 to 5-n is the same as that of the output connector of the control voltage generation unit 5-1. That is, the output connectors of the control voltage generation units 5-2 to 5-n are connected to the inputs of current target value setting circuits provided in the DC-DC converters 3-2 to 3-n, respectively.

  The ground of the power source 2, the first ground of the DC-DC converters 3-1 to 3-n, the second ground of the DC-DC converters 3-1 to 3-n, and the other end of the load 7 are Electrically grounded.

  Note that a current target value setting circuit (16-1 and the like) included in the DC-DC converters 3-1 to 3-n will be described later with reference to FIG. The male connector (12a-1), female connector (12b-1), and output connector (11-1) of the control voltage generation unit 5-1 will be described later with reference to FIG.

(Operation of power supply 1)
First, as shown in FIG. 1 and the description of (configuration of the power supply device 1), in the power supply device 1 of the first embodiment, the DC-DC converters 3-1 to 3-n are connected between the power supply 2 and the load 7. Are connected in parallel. The load 7 is preferably a load that requires n DC-DC converters 3-1 to 3-n or prepare n DC-DC converters 3-1 to 3-n.

  The power source 2 supplies first DC power to the DC-DC converters 3-1 to 3-n. The power source 2 is, for example, an AC-DC converter, converts AC power input from a commercial AC power source into first DC power, and supplies the first DC power to the DC-DC converters 3-1 to 3-n.

  The DC-DC converter 3-1 supplies the second DC power to the load 7 based on the first DC power. When the second DC power is supplied to the load 7, a DC current I1 that is a current corresponding to the second DC power is output to the node N1 via the backflow prevention diode D-R1.

  The DC-DC converters 3-2 to 3-n perform the same operation as the DC-DC converter 3-1. That is, the DC-DC converters 3-2 to 3-n supply the second DC power to the load 7 based on the first DC power. At the same time, DC currents I2 to In that are currents corresponding to the second DC powers are output to the node N1 via the backflow prevention diodes D-R1 to D-Rn, respectively.

DC currents I1 to In are input to the node N1. Therefore, the load current Itotal, which is the current supplied from the node N1 to the load 7, is
Itotal = I1 + I2 + I3 +... + In (1)
It becomes. Therefore, even when the power required by the load 7 is large (that is, when the load current Itotal that is a current flowing to the load 7 is large), the plurality of DC-DC converters 3-1 to 3-n Electric power and current required by the load 7 can be supplied.

  In the above description, the load current Itotal is supplied by n DC-DC converters 3-1 to 3-n. However, it is preferable to supply the load current Itotal with (n-1) or (n-2) DC-DC converters. By using at least one, preferably two DC-DC converters as a spare, the reliability of the power supply device 1 can be improved.

  Here, as described above, the first current generation unit 4 includes a detection unit 4a and an output unit 4b. A load current Itotal that is a current supplied from the node N1 to the load 7 flows through the detection unit 4a. The output unit 4b outputs a current Ir (first current) that is a current corresponding to a load current Itotal that is a current flowing through the detection unit 4a to the control voltage generation unit 5-1.

  The current Ir flows through the path of the control voltage generation unit 5-1 → the control voltage generation unit 5-2 → the control voltage generation unit 5-3 →... → the control voltage generation unit 5 -n → the termination unit 6. This will be described later with reference to FIG.

  Each of the control voltage generation units 5-1 to 5-n includes a shunt resistor 14. The shunt resistors 14 will be described later with reference to FIG. 3. The resistance values of the n shunt resistors 14 that are the same as the number of the control voltage generation units 5-1 to 5-n are as follows. That is, the resistance value of the shunt resistor is a resistance value corresponding to a direct current that is a current output from the corresponding DC-DC converter. Specifically, the resistance values of the n shunt resistors 14 are equal to or substantially equal to each other. Further, the accuracy of the resistance value of the shunt resistor 14 is very high, and the tolerance of the resistance value is ± 0.5%.

  In the control voltage generating units 5-1 to 5-n, the same current Ir flows through the shunt resistors 14 having the same resistance value. As a result, the control voltage generation units 5-1 to 5-n are voltages corresponding to the current Ir and the shunt resistors 14-1 to 14-n. It can be output to the input of the current target value setting circuit included in the converters 3-1 to 3-n.

  The DC-DC converters 3-1 to 3-n control the direct currents I1 to In output by the DC-DC converters 3-1 to 3-n according to the value of the control voltage Vr input to the input of the current target value setting circuit included therein. To do).

As described above, the power supply device 1 according to the first embodiment includes the first current generation unit 4, the control voltage generation units 5-1 to 5-n, and the termination unit 6. Thereby, the equal control voltage Vr is automatically input to the input of the current target value setting circuit included in each DC-DC converter. Therefore, the target value of the current output from each DC-DC converter is automatically equalized, and the direct currents I1 to In are controlled to be equal to each other. Therefore,
I1 = I2 = I3 = ... = In (2)
Is established. In addition, from Equation (1) and Equation (2),
Itotal = n × In (3)
It becomes.

  Thus, as a result of the direct currents I1 to In being equal to each other, the load applied to the DC-DC converters 3-1 to 3-n is equalized. Therefore, the temperatures of the DC-DC converters 3-1 to 3-n are also equal to each other (that is, thermal equilibrium can be achieved).

  Regarding the reliability of the power supply device, when only one DC-DC converter among the plurality of DC-DC converters has an output current larger than the other, only the one DC-DC converter has a temperature higher than the other. Becomes higher. In this case, only the parts constituting the one DC-DC converter have a higher temperature than the others, and the reliability as a power supply device is impaired. Specifically, the service life is shortened or the probability of failure is increased.

  However, in the power supply device 1 according to the first embodiment, the direct currents I1 to In that are currents output from the DC-DC converters are equal to each other. Thereby, the current output from a specific DC-DC converter does not become larger than the current output from other DC-DC converters. Therefore, the temperature of the specific DC-DC converter does not become higher than that of other DC-DC converters. Therefore, higher reliability than the conventional power supply device can be obtained.

  Further, the life of the DC-DC converter changes depending on its own temperature, but the DC-DC converters 3-1 to 3 -n have the same temperature, and thus the DC-DC converters 3-1 to 3 -n. The lifespan is equal. As a result, it is possible to provide the power supply device 1 having higher reliability than the conventional power supply device.

  The current Ir is a current corresponding to the load current Itotal. Therefore, when the load current Itotal varies, the current Ir also varies according to the variation. The control voltage Vr also varies according to the current Ir.

  However, similarly to the control voltage Vr before the fluctuation, the control voltage Vr after the fluctuation is an equal voltage for each DC-DC converter. Therefore, even if the load current Itotal fluctuates, the current target value is automatically changed to a value corresponding to the load applied to each DC-DC converter. In the first embodiment, the target value of current is always equal between the DC-DC converters. Therefore, the direct currents I1 to In output from the DC-DC converters are controlled to be equal to the currents according to the capabilities of the DC-DC converters, and are equalized.

  In the power supply device 1 according to the first embodiment, at least two DC-DC converters 3-1 to 3-n are connected in parallel to the load 7, and each DC-DC converter supplies power. Thus, the power supply device supplies power to the load.

  The power supply device 1 includes the following components. First, a first current generation unit 4 that generates a current Ir corresponding to a load current Itotal that is a current flowing through the load 7 is provided.

  Secondly, one control voltage generating unit 5-1 to five for generating a control voltage Vr for controlling a current output from each DC-DC converter is provided for one DC-DC converter. n.

  For the control voltage Vr, the potential difference between the output unit 4b from which the first current generating unit 4 outputs the current Ir and the termination unit 6 for determining the potential of the output unit 4b is proportional to the capability of each DC-DC converter. Then, it is generated by dividing each DC-DC converter. When the capabilities of the DC-DC converters are the same, the control voltages are the same. That is, the potential difference is divided equally.

  Furthermore, since the control voltage generation units 5-1 to 5-n are connected by the male connector and the female connector, the connection becomes easier.

(Configuration of DC-DC converter)
Here, the DC-DC converters 3-1 to 3-n according to the first embodiment will be described with reference to FIG. FIG. 2 is a circuit diagram of the DC-DC converter 3-1 according to the first embodiment. The load 7 shown in FIG. 2 is conceptually the same as the load 7 shown in FIG.

  The DC-DC converter 3-1 includes capacitors C1-1 and C2-1, an inductor L-1, a diode D-1, and a switching element Q-1.

  The DC-DC converter 3-1 includes a controller 8-1 (comparison unit), a PI operation unit 9-1, a comparator 10-1, a second current generation unit 15-1, and a current target value setting circuit 16-. 1 (current target value setting unit). The controller 8-1, the PI operation unit 9-1, the comparator 10-1, the second current generation unit 15-1, and the current target value setting circuit 16-1 constitute a control system 17-1.

  Furthermore, the second current generation unit 15-1 includes a detection unit and an output unit.

  FIG. 2 is a diagram of the DC-DC converter 3-1, but the circuit configuration of the DC-DC converter 3-2 to the DC-DC converter 3-n is the same as that of the DC-DC converter 3-1. .

  That is, the DC-DC converter 3-n includes capacitors C1-n and C2-n, an inductor Ln, a diode Dn, and a switching element Qn.

  The DC-DC converter 3-n includes a controller 8-n, a PI operation unit 9-n, a comparator 10-n, a second current generation unit 15-n, and a current target value setting circuit 16-n. Yes. The controller 8-n, the PI operation unit 9-n, the comparator 10-n, the second current generation unit 15-n, and the current target value setting circuit 16-n constitute a control system 17-n.

  In the DC-DC converter 3-1 of FIG. 2, the output of the power supply 2 of the power supply device 1 is connected to one end of the inductor L-1 and one end of the capacitor C1-1.

  The other end of the inductor L-1 is connected to the anode of the diode D-1 and the collector of the switching element Q-1.

  The cathode of the diode D-1 is connected to one end of the detection unit of the second current generation unit 15-1 and one end of the capacitor C2-1. The other end of the detection unit of the second current generation unit 15-1 is connected to the anode of the backflow prevention diode D-R 1 of the power supply device 1.

  The cathode of the backflow prevention diode D-R1 of the power supply device 1 is connected to one end of the load 7 via the node N1 of the power supply device 1 and the detection unit 4a of the first current generating unit 4 of the power supply device 1. Yes. In FIG. 2, the node N1 of the power supply device 1 and the first current generation unit 4 of the power supply device 1 are not shown.

  The output part of the 2nd electric current production | generation part 15-1 is connected to the 1st input of the controller 8-1. The second input of the controller 8-1 is connected to the output of the current target value setting circuit 16-1. The control voltage Vr is input from the output connector 11-1 included in the control voltage generation unit 5-1 of the power supply device 1 to the input of the current target value setting circuit 16-1.

  The first output of the controller 8-1 is connected to one end of the PI operation unit 9-1. A second output of the controller 8-1 is connected to an input of an output connector 11-1 included in the control voltage generation unit 5-1. The other end of the PI operation unit 9-1 is connected to the non-inverting input terminal (+) of the comparator 10-1. The carrier signal carrier is input to the inverting input terminal (−) of the comparator 10-1. The output of the comparator 10-1 is connected to the base of the switching element Q-1.

  The ground of the power source 2, the other end of the capacitor C1-1, the emitter of the switching element Q-1, the other end of the capacitor C2-1, and the other end of the load 7 are electrically grounded.

(Operation of DC-DC converter)
In the DC-DC converter 3-1, the first DC power is first supplied from the power source 2 to the DC-DC converter 3-1. That is, a current flows from the power supply 2 to one end of the inductor L-1. Since this current includes an alternating current component, the high frequency component is removed by the capacitor C1-1.

  The current output from the inductor L1-1 becomes a current having a waveform including a rectangular pulse by switching control, which is control for alternately turning on and off the switching element Q-1.

  The current after switching control is rectified by the diode D-1. From the rectified current, the high frequency component is removed by the capacitor C2-1. Thereby, the direct current I1 can be output to the outside of the DC-DC converter 3-1.

  The direct current I1 flows through a path of the second current generation unit 15-1 from the detection unit → the backflow prevention diode DR1-R1.

  Next, control of the direct current I1 will be described. When the direct current I1 is output to the outside of the DC-DC converter 3-1, the direct current I1 also flows through the detection unit of the second current generation unit 15-1.

  When the direct current I1 flows through the detection unit of the second current generation unit 15-1, a current Ir1 (second current) that is a current corresponding to the direct current I1 is generated from the output unit of the second current generation unit 15-1. Is done. The current Ir1 output from the second current generator 15-1 is input to the first input of the controller 8-1.

  Further, as described above, the control voltage Vr is input to the input of the current target value setting circuit 16-1 from the output of the output connector 11-1 included in the control voltage generation unit 5-1. Based on the control voltage Vr, the current target value setting circuit 16-1 outputs a target current It that is a current indicating the target value (current target value) of the direct current I1 to the second input of the controller 8-1.

  The controller 8-1 compares the current Ir1, which is a current corresponding to the DC current I1, and the target current It, and a control signal Sc which is a signal corresponding to the comparison result and which is an analog signal is converted into a PI operation. Output to unit 9-1.

  Regarding the comparison of the two currents in the controller 8-1, first, when the current Ir1 is smaller than the target current It, the level of the control signal Sc is made higher. Second, when the current Ir1 is larger than the target current It, the level of the control signal Sc is made lower. Third, when the current Ir1 is equal to the target current It, the level of the control signal Sc is maintained.

  As the level of the control signal Sc becomes higher, the pulse width for turning on the switching element Q-1 becomes wider in the pulse signal Sp described later. On the other hand, when the level of the control signal Sc becomes lower, the pulse width for turning on the switching element Q-1 becomes narrower in the pulse signal Sp.

  The control signal Sc output from the controller 8-1 is input to the PI operation unit 9-1. P of PI action shows proportional action (P action), I of PI action shows integral action (integral action, I action).

  The PI operation unit 9-1 compensates the stability and quick response of the control system 17-1 that controls the DC current I1 by the P operation. By adding the I operation to the P operation, the offset with respect to the disturbance is removed.

  The signal after the PI operation is performed by the PI operation unit 9-1 is input to the non-inverting input terminal (+) of the comparator 10-1. The carrier signal carrier is input to the inverting input terminal (−) of the comparator 10-1.

  The comparator 10-1 generates a pulse signal Sp including a rectangular pulse by comparing the signal after the PI operation is performed with the carrier signal carrier. The comparator 10-1 outputs the generated pulse signal Sp from its own output to the base of the switching element Q-1.

  The switching element Q-1 is alternately turned on / off according to the pulse signal Sp input to its base. Thereby, the DC-DC converter 3-1 can perform the switching control and output the direct current I1. Similarly, the DC-DC converters 3-2 to 3 -n can perform switching control and output DC currents I 2 to In.

(Configuration of control voltage generation unit)
Here, the control voltage generation units 5-1 to 5-n according to the first embodiment will be described with reference to FIG. FIG. 3 is a circuit diagram of the control voltage generation unit 5-1 according to the first embodiment.

  The control voltage generation unit 5-1 includes an output connector 11-1, a male connector 12a-1, a female connector 12b-1, a relay circuit 13-1, and a shunt resistor 14-1. The output connector 11-1 includes a first output terminal 11a-1, a second output terminal 11b-1, a first input terminal 11c-1, and a second input terminal 11d-1. Furthermore, the relay circuit 13-1 includes an inductor Lr-1 and a changeover switch SW-1.

  The “input” and “output” included in the names of the terminals 11a-1 to 11d-1 mean inputs and outputs to the DC-DC converter 3-1 to which the output connector 11-1 is connected. ing. FIG. 3 is a diagram of the control voltage generation unit 5-1, but the circuit configuration of the control voltage generation unit 5-2 to the control voltage generation unit 5-n is the same as that of the control voltage generation unit 5-1. .

  The control voltage generation unit 5-n includes an output connector 11-n, a male connector 12a-n, a female connector 12b-n, a relay circuit 13-n, and a shunt resistor 14-n. The output connector 11-n includes a first output terminal 11a-n, a second output terminal 11b-n, a first input terminal 11c-n, and a second input terminal 11d-n. Further, the relay circuit 13-n includes an inductor Lr-n and a changeover switch SW-n.

  In the control voltage generation unit 5-1 of FIG. 3, the male connector 12 a-1 is connected to the output unit 4 b of the first current generation unit 4 of the power supply device 1. The output of the male connector 12a-1 is connected to the first output terminal 11a-1 and the first terminal of the changeover switch SW-1.

  A second terminal (NO) of the changeover switch SW-1 is connected to one end of the shunt resistor 14-1. The other end of the shunt resistor 14-1 is connected to the second output terminal 11b-1, the third terminal (NC) of the changeover switch SW-1, and the input of the female connector 12b-1.

  The female connector 12b-1 is connected to the male connector 12a-2 of the control voltage generation unit 5-2 at the next stage.

  In the control voltage generation unit 5-1, the output of the female connector 12b-1 and the input of the male connector 12a-1 are connected to each other.

  As shown in FIG. 2, in the state where the DC-DC converter 3-1 is connected to the load 7, the voltage applied to the two positive and negative output terminals of the DC-DC converter 3-1 is the first input terminal 11c-1. And applied to the second input terminal 11d-1. However, not limited to this configuration, an arbitrary voltage indicating a state in which the DC-DC converter 3-1 is operated is applied to the first input terminal 11c-1 and the second input terminal 11d-1. It may be. Examples of the arbitrary voltage include a voltage generated by the controller 8-1 according to the current Ir1.

(Operation of control voltage generation unit)
The operation of the control voltage generation unit 5-1 in FIG. 3 will be described below. First, when the DC-DC converter 3-1 is operating normally (not faulty), both ends of the inductor Lr-1 (that is, the first input terminal 11c-1 and the second input terminal 11d-1) In the meantime, a voltage indicating the state in which the DC-DC converter 3-1 operates is applied.

  The relay circuit 13-1 works by applying the voltage across the inductor Lr-1. Thereby, in the changeover switch SW-1 of the relay circuit 13-1, the first terminal and the second terminal (NO) are connected. Accordingly, the current Ir flows through the path of one terminal of the male connector 12a-1 → the changeover switch SW-1 → the shunt resistor 14-1 → one terminal of the female connector 12b-1.

  When the DC-DC converter 3-1 is not operating normally (failed), no voltage is applied across the inductor Lr-1, so the relay circuit 13-1 does not work. Therefore, in the changeover switch SW-1 of the relay circuit 13-1, the first terminal and the third terminal (NC) are connected (normally closed). Therefore, the current Ir flows through the path of one terminal of the male connector 12a-1 → the changeover switch SW-1 → one terminal of the female connector 12b-1.

  On the other hand, when the DC-DC converter 3-1 is operating normally, a current flows through the shunt resistor 14-1 so that the first output terminal 11 a-1 and the second output terminal 11 b-1 are connected. Then, a control voltage Vr is generated. The control voltage Vr is input to the current target value setting circuit 16-1 via the output connector 11-1. Therefore, the DC-DC converter 3-1 can output a direct current I1 corresponding to the control voltage Vr.

  The control voltage generation units 5-2 to 5-n operate in the same manner as the control voltage generation unit 5-1. That is, the control voltage generation units 5-2 to 5-n output the control voltage Vr to the current target value setting circuits 16-2 to 16-n, respectively. Therefore, the DC-DC converters 3-2 to 3-n can output direct currents I2 to In corresponding to the control voltage Vr, respectively.

  Further, the current Ir flows from the other terminal of the female connector 12b-1 to the other terminal of the male connector 12a-1. This point will be described later with reference to (current Ir) and FIG.

  As described above, the control voltage generation units 5-1 to 5-n according to the first embodiment are mounted on the power supply device 1. First, the power supply device 1 includes at least two DC-DC converters connected in parallel to the load 7. Second, each DC-DC converter supplies power to the load 7 to generate a current Ir corresponding to a load current Itotal that is a current flowing through the load 7. Is provided.

  One control voltage generation unit 5-1 to 5-n is provided for one DC-DC converter. The potential difference between the output unit 4b from which the first current generating unit 4 outputs the current Ir and the termination unit 6 for determining the potential of the output unit 4b is divided equally for each DC-DC converter. To do. Thereby, the equal control voltage Vr for controlling the current output from each DC-DC converter is generated.

  Further, the control voltage generation units 5-1 to 5-n include the following components. First, one shunt resistor 14-1 to 14-n having the same resistance value is provided for each DC-DC converter. Second, shunt resistors 14-1 to 14-n and relay circuits 13-1 to 13-n corresponding one-to-one are provided.

  The n shunt resistors 14-1 to 14-n are connected in series between the output unit 4b and the termination unit 6 to constitute a voltage dividing circuit, and the shunt resistors 14-1 to 14- Each of n generates the control voltage Vr.

  The relay circuit 13-1 is switched between two states by a changeover switch SW-1 (switch circuit). The first state is an ON state in which the control voltage Vr for controlling the output of the corresponding DC-DC converter is generated when the current Ir flows through the shunt resistor 14-1. The second state is an off state in which the current Ir does not flow through the shunt resistor 14-1.

  The relay circuit 13-1 turns on the changeover switch SW-1 in conjunction with the operation of the corresponding DC-DC converter if the corresponding DC-DC converter 3-1 has not failed.

  As a result, a voltage is applied from the DC-DC converter 3-1 to the inductor Lr-1, and the current Ir flows through the shunt resistor 14-1, whereby the control voltage Vr that is a voltage for controlling the direct current I1. Is generated and output to the DC-DC converter 3-1.

  On the other hand, if the DC-DC converter 3-1 has failed, the changeover switch SW-1 is turned off. As a result, no voltage is applied from the DC-DC converter 3-1 to the inductor Lr-1. Therefore, the control voltage Vr can be prevented from being generated by preventing the current Ir from flowing through the shunt resistor 14-1. Therefore, it is possible not to use the failed DC-DC converter 3-1 (exclude the DC-DC converter that is not operating).

(Current Ir)
As described above, the current Ir is output from the first current generation unit 4 to the control voltage generation unit 5-1. In this section, how the current Ir flows in the power supply device 1 according to the first embodiment will be described with reference to FIG.

  Note that the first current generation unit 4 in FIG. 4 is merely an example. The first current generation unit 4 only needs to be capable of outputting the current Ir from the output unit 4b to one terminal of the male connector 12a-1 when the load current Itotal flows through the detection unit 4a.

  FIG. 4 is an explanatory diagram for explaining how the current Ir flows in the power supply device 1 according to the first embodiment. For convenience of explanation, FIG. 4 is a diagram in the case where there are two control voltage generation units (that is, two DC-DC converters).

  As shown in FIG. 4, a load current Itotal that is a current supplied from the node N <b> 1 to the load 7 flows through the detection unit 4 a of the first current generation unit 4. The detection unit 4a is a hot wire (heater), and generates Joule heat when the load current Itotal flows.

  The output unit 4b of the first current generation unit 4 is a thermocouple. The output unit 4b, which is a thermocouple, includes a first metal 4b1 and a second metal 4b2.

  In FIG. 4, one end of the first metal 4b1 and one end of the second metal 4b2 are connected at one point of the detection unit 4a.

  The other end of the first metal 4b1 is connected to one terminal of the male connector 12a-1. One terminal of the female connector 12b-1 is connected to one terminal of the male connector 12a-2.

  One terminal of the female connector 12b-2 and the other terminal of the female connector 12b-2 are short-circuited inside the termination unit 6.

  The other terminal of the male connector 12a-2 is connected to the other terminal of the female connector 12b-1.

  The other terminal of the male connector 12a-1 is connected to the other end of the second metal 4b2.

  According to the above configuration, when the load current Itotal flows through the detection unit 4a that is a hot wire (heater), thermoelectromotive force is generated at both ends of the output unit 4b that is a thermocouple. As described above, since the control voltage generation units 5-1 and 5-2 have shunt resistors having the same resistance value, the current Ir can be caused to flow by the thermoelectromotive force and the shunt resistor.

  In order to pass the current Ir in the direction shown in FIG. 4, for example, the first metal 4b1 may be zinc and the second metal 4b2 may be platinum. Thereby, a thermoelectromotive force of +0.76 mV can be obtained.

  The second current generation unit 15-1 in FIG. 2 may also be realized by a hot wire and a thermocouple, similarly to the first current generation unit 4 in FIG.

  Thus, in the power supply device 1, the control voltage generation unit 5-1 includes the shunt resistor 14-1 having a resistance value proportional to the capability of the corresponding DC-DC converter. And the shunt resistance 14-1 provided in each control voltage generation unit may be connected in series between the output unit 4b and the termination unit 6.

  Thereby, the divided control voltage can be generated according to the value of the shunt resistor. And when the capability of each DC-DC converter is the same, the shunt resistance 14-1 can be set to the same resistance value, and the equally divided control voltage Vr can be generated.

(Summary of Embodiment 1)
In order to obtain a desired electric power, when a plurality of DC-DC converters having the same ability are connected and operated in parallel, the following configuration is adopted in order to load each device equally. That is, the target current value of each DC-DC converter is automatically set to an equal value based on the load current Itotal without being set in advance.

  If each current target value is not uniform, the temperature (operating temperature) of a DC-DC converter with a large burden will rise, the burden on components will increase, and reliability will be impaired.

  FIG. 1 shows the overall configuration of the power supply device 1. As shown in FIG. 1, n DC-DC converters are connected in parallel to obtain a desired power. A control voltage generation unit is provided corresponding to each DC-DC converter.

  In the power supply device 1, the first current generation unit 4 is provided on the line through which the load current Itotal flows. Further, the control voltage generation units 5-1 to 5-n connected to the DC-DC converter by a cable or the like are connected using a male connector and a female connector.

  Each control voltage generation unit is connected by a male connector and a female connector. Therefore, a plurality of control voltage generation units can be connected in series. The termination unit 6 is connected to the final control voltage generation unit.

  Each control voltage generating unit 5-1 to 5-n is provided with a shunt resistor having high accuracy and the same resistance value.

  The voltage generated by the load current Itotal is divided by the number of control voltage generation units by simply connecting the control voltage generation units corresponding to each DC-DC converter in series. The divided voltage is input as a control voltage Vr to a current target value setting circuit included in each DC-DC converter.

  Moreover, the potential difference between the output unit 4b of the first current generation unit 4 and the termination unit 6 can be equalized only by connecting in series the control voltage generation units each having a shunt resistor having the same resistance value. The control voltage Vr can be generated by dividing. As a result, the current target value can be made uniform, so that it is not necessary to set the current target value in advance in DC-DC converters that operate in parallel. Further, even when the power consumption of the load 7 fluctuates, the control voltage Vr in which the potential difference is equally divided can be generated following the fluctuation.

  When the connected DC-DC converter is not operating due to a failure or the like, the relay circuit included in the control voltage generation unit does not work. Therefore, the current Ir bypasses the shunt resistor via the NC terminal side (does not flow to the shunt resistor). For this reason, the resistance value of the shunt resistor included in the control voltage generation unit corresponding to the DC-DC converter that is not operating is not added to the closed circuit through which the current Ir flows. Therefore, an accurate control voltage Vr can be generated by excluding the DC-DC converter that is not operating. The above operation can be realized with a simple configuration as shown in FIGS.

  The current target value is input to the current target value setting circuit (16-1) in FIG. Then, the target current It output from the current target value setting circuit is compared with the direct current I1 output from the DC-DC converter 3-1, and the direct current I1 is controlled to match the target current It.

[Embodiment 2]
The following will describe another embodiment of the present invention with reference to FIGS. The configurations other than those described in the present embodiment are the same as those in the first embodiment. For convenience of explanation, members having the same functions as those shown in the drawings of Embodiment 1 are given the same reference numerals, and descriptions thereof are omitted.

  The differences between the second embodiment and the first embodiment are as follows. First, in the power supply device 21 of FIG. 5, the capabilities of the DC-DC converters 23-1 to 23-n are not the same. That is, the maximum value of power that can be output by the DC-DC converters 23-1 to 23-n (that is, the maximum value of current) is not the same. This will be described later in (Operation of power supply device 21). Further, the resistance values of the shunt resistors inside the control voltage generation units 25-1 to 25-n are not the same.

  FIG. 5 is a block diagram of the power supply device 21 according to the second embodiment. The power supply device 21 includes DC-DC converters 23-1 to 23-n and control voltage generation units 25-1 to 25-n that correspond one-to-one with the DC-DC converters 23-1 to 23-n. ing. Other configurations are the same as those of the power supply device 1 according to the first embodiment.

(Operation of the power supply device 21)
In the power supply device 21 of FIG. 5, the DC-DC converters 23-2 to 23-n perform the same operation as the DC-DC converter 23-1, but have different direct-current power to be supplied, in other words, capabilities. That is, the DC-DC converters 23-1 to 23-n supply different DC powers to the load 7 based on the first DC power. At the same time, DC currents I2 ′ to In ′, which are currents corresponding to different DC powers, are output to the node N3 via the backflow prevention diodes D-R1 to D-Rn, respectively.

  DC currents I1 'to In' are input to the node N3. Therefore, the load current Itotal that is the current supplied from the node N3 to the load 7 is expressed by the equation (1) in the first embodiment.

  The current Ir ′ flows through the path of the control voltage generation unit 25-1 → the control voltage generation unit 25-2 → the control voltage generation unit 25-3 →... → the control voltage generation unit 25 -n → the termination unit 6. This will be described later with reference to FIG.

  The control voltage generation units 25-1 to 25-n include shunt resistors 14-1 'to 14-n'. The shunt resistors 14-1 ′ to 14-n ′ will be described later with reference to FIG. 6. The resistance values of the n shunt resistors included in the control voltage generation units 25-1 to 25-n are as follows. It is. That is, the resistance value of the shunt resistor is a resistance value corresponding to a direct current that is a current output from the corresponding DC-DC converter. Specifically, the resistance value of the shunt resistor 14-1 ′ is R, the resistance value of the shunt resistor 14-2 ′ is 2 × R, the resistance value of the shunt resistor 14-3 ′ is 3 × R, and the shunt resistor 14-n. The resistance value of 'is n × R.

Here, the following formulas are established for the direct currents I1 ′ to In ′.
I2 ′ = 2 × I1 ′ (4)
I3 ′ = 3 × I1 ′ (5)
In ′ = n × I1 ′ (6)
(Configuration of control voltage generation unit)
Here, the control voltage generation units 25-1 to 25-n according to the second embodiment will be described with reference to FIG. FIG. 6 is a circuit diagram of the control voltage generation unit 25-1 according to the second embodiment.

  The control voltage generation unit 25-1 includes a shunt resistor 14-1 'and a replaceable shunt resistor module 30-1. Since the shunt resistor 14-1 'is accommodated in the replaceable shunt resistor module 30-1, the shunt resistor 14-1' can be replaced. Other configurations are the same as those of the control voltage generation unit 5-1 of the first embodiment.

  Similarly, the control voltage generation unit 25-n includes a shunt resistor 14-n ′ and a replaceable shunt resistor module 30-n. Since the shunt resistor 14-n 'is housed in the replaceable shunt resistor module 30-n, the shunt resistor 14-n' can be replaced. Other configurations are the same as those of the control voltage generation unit 5-n of the first embodiment.

  In the control voltage generation unit 25-1 in FIG. 6, the second terminal (NO) of the changeover switch SW-1 is connected to one end of the shunt resistor 14-1 ′ via one end of the replaceable shunt resistor module 30-1. Has been. The other end of the shunt resistor 14-1 ′ is connected to the second output terminal 11b-1, the third terminal (NC) of the changeover switch SW-1, and the female via the other end of the replaceable shunt resistor module 30-1. It is connected to the input of the mold connector 12b-1.

(Operation of control voltage generation unit)
The operation of the control voltage generation unit 25-1 in FIG. 6 will be described below.

  When the DC-DC converter 23-1 is operating normally and a current flows through the shunt resistor 14-1 ′, a control voltage is generated between the first output terminal 11a-1 and the second output terminal 11b-1. Vr1 is generated. The control voltage Vr1 is input to the current target value setting circuit provided in the DC-DC converter 23-1 via the output connector 11-1. Accordingly, the DC-DC converter 23-1 can output a direct current I1 'corresponding to the control voltage Vr1.

  The control voltage generation units 25-2 to 25-n operate in the same manner as the control voltage generation unit 25-1. That is, the control voltage generation units 25-2 to 25-n output the control voltages Vr2 to Vrn to current target value setting circuits provided in the DC-DC converters 23-2 to 23-n, respectively. Accordingly, the DC-DC converters 23-2 to 23-n can output DC currents I2 'to In' corresponding to the control voltages Vr2 to Vrn, respectively.

(Summary of Embodiment 2)
In a power supply device (system) that obtains desired power by connecting a plurality of DC-DC converters having different capacities and operating them in parallel, when a uniform current target value is set for each DC-DC converter, The load current of the DC-DC converter becomes equal.

  However, each of the DC-DC converters 23-1 to 23-n of the second embodiment has different capabilities. For this reason, if an equal current target value is set for each DC-DC converter, the ratio of the load to the capability of each DC-DC converter will differ.

  As the ratio of the load to the capacity increases, the temperature of the power supply device increases and the burden on each component increases. For this reason, the power supply device is likely to break down. Therefore, in a power supply device including a plurality of DC-DC converters, the time when a failure of each DC-DC converter occurs is different. Accordingly, the operable period of the entire power supply device is shortened, and as a result, the long-term reliability of the power supply device is impaired.

  Therefore, the power supply device 21 according to the second embodiment employs the following configuration. That is, when a plurality of DC-DC converters having different capacities are connected and operated in parallel, the target current value is set so that the ratio of the load to the capacity becomes equal.

  As a result, variation in heat generation in each DC-DC converter can be suppressed, and the uneven burden on the components can be eliminated. Therefore, it is possible to eliminate the bias in the probability of failure and to ensure the long-term reliability of the power supply device.

  As a specific method, the resistance value of the shunt resistor provided in the control voltage generation unit attached to each DC-DC converter is set in proportion to the capability of each DC-DC converter.

  Thereby, the resistance value of the shunt resistor becomes the resistance value of the shunt resistor according to the capability of each DC-DC converter, and the target current also becomes the value according to the capability of each DC-DC converter.

  For example, as illustrated in FIG. 5, the resistance value of the shunt resistor 14-1 ′ of the control voltage generation unit 25-1 corresponding to the DC-DC converter 23-1 having a unit of capability is set to 1. At this time, the resistance value of the shunt resistor 14-2 ′ of the control voltage generation unit 25-2 corresponding to the DC-DC converter 23-2 whose capacity unit is double is set to the resistance value of the shunt resistor 14-1 ′. Double.

  Similarly, the resistance value of the shunt resistor 14-n ′ of the control voltage generation unit 25-n corresponding to the DC-DC converter 23-n whose capacity unit is n times is n of the resistance value of the shunt resistor 14-1 ′. Double.

  By setting it as such a structure, the electric current target value of the magnitude | size according to each capability can be input into each DC-DC converter. As a result, each DC-DC converter can output a current corresponding to its own capacity, so that the ratio of the load to the capacity can be made constant.

  Therefore, the temperature of a specific DC-DC converter does not become higher than other DC-DC converters. Therefore, higher reliability than the conventional power supply device can be obtained.

  Furthermore, the lifetime of the DC-DC converter varies depending on its own temperature, but since the temperature of each DC-DC converter is equal, the lifetime of each DC-DC converter is also equal. As a result, higher reliability than the conventional power supply device can be obtained.

  Further, the shunt resistor (14-1 ') of the control voltage generating unit (25-1) is inserted (accommodated) into the replaceable shunt resistor module (30-1) as shown in FIG. The resistance value of the shunt resistor in the control voltage generation unit can be changed by inserting a replaceable shunt resistor module into the shunt resistor having a magnitude corresponding to the capability of the DC-DC converter.

  When the connected DC-DC converter is not operating due to a failure or the like, the relay circuit included in the control voltage generation unit does not work. Therefore, the current Ir ′ bypasses the shunt resistor via the NC terminal side (does not flow to the shunt resistor). For this reason, the resistance value of the shunt resistor included in the control voltage generation unit corresponding to the DC-DC converter that is not operating is not added to the closed circuit through which the current Ir ′ flows. Accordingly, it is possible to generate accurate control voltages Vr1 to Vrn by excluding a DC-DC converter that is not operating. The above operation can be realized with a simple configuration as shown in FIGS.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  Since the power supply device of the present invention has higher reliability than the conventional power supply device, it can be suitably used for a power supply device mounted on an electric vehicle.

DESCRIPTION OF SYMBOLS 1,21 Power supply device 2 Power supply 3-1 to 3-n, 23-1 to 23-n DC-DC converter 4 1st electric current generation unit (1st electric current generation part)
4a detection unit 4b output unit 4b1 first metal 4b2 second metal 5-1 to 5-n, 25-1 to 25-n control voltage generation unit (control voltage generation unit)
6 Termination unit 7 Load 8-1, 8-n Controller (comparison part)
9-1, 9-n PI operation unit 10-1, 10-n comparator 11-1, 11-n output connector 11a-1, 11a-n first output terminal 11b-1, 11b-n second output terminal 11c -1, 11c-n First input terminal 11d-1, 11d-n Second input terminal 12a-1, 12a-2, 12a-n Male connector 12b-1, 12b-2, 12b-n Female connector 13 -1, 13-n Relay circuit 14-1 to 14-n, 14-1 'to 14-n' Shunt resistor 15-1, 15-n Second current generator 16-1 to 16-n Current target value setting Circuit (current target value setting part)
17-1, 17-n Control system 30-1, 30-n Interchangeable shunt resistor module C1-1, C1-n Capacitor C2-1, C2-n Capacitor D-1, Dn Diode D-R1-D -Rn Backflow prevention diodes I1 to In, I1 'to In' DC current Ir, Ir 'current (first current)
Ir1 current (second current)
It Target current Ital Load current L-1, Ln, L1-1 Inductor Lr-1, Lr-n Inductor N1-N4 Node Q-1, Qn Switching element SW-1, SW-n Switch Sc Control signal Sp pulse signal Vr, Vr1 to Vrn Control voltage carrier Carrier signal

Claims (7)

At least two DC-DC converters are connected in parallel to the load;
Each DC-DC converter is a power supply device that supplies power to a load by supplying power,
A first current generator that generates a first current according to a load current that is a current flowing through the load;
One is provided for one DC-DC converter, and a potential difference between an output unit from which the first current generator outputs the first current and a terminal unit that determines the potential of the output unit is provided. And a control voltage generator that generates a control voltage for controlling the current output from each DC-DC converter by dividing the DC-DC converter for each DC-DC converter in proportion to the capability of each DC-DC converter. A power supply device characterized by that.   The control voltage generation unit includes a shunt resistor having a resistance value proportional to the capability of the corresponding DC-DC converter, and the shunt resistor included in each control voltage generation unit includes the output unit and the termination unit. The power supply device according to claim 1, wherein the power supply devices are connected in series. The DC-DC converter is
A second current generation unit that generates a second current according to the direct current output by itself;
A current target value setting unit that generates a target current that is a target value of the DC current in accordance with the control voltage;
The power supply apparatus according to claim 2, further comprising a comparison unit that compares the second current with the target current. The maximum current that each DC-DC converter can output is the same,
4. The power supply device according to claim 1, wherein resistance values of the shunt resistors are all equal. The maximum current that each DC-DC converter can output is different.
4. The power supply device according to claim 1, wherein a resistance value of each shunt resistor is proportional to a maximum value of a current that can be output by a corresponding DC-DC converter. The control voltage generation unit includes a relay circuit, and includes an inductor that operates the relay circuit.
A voltage output from the corresponding DC-DC converter is applied to the inductor. If the corresponding DC-DC converter is not broken, a voltage is applied from the DC-DC converter to the inductor, and the shunt resistor is applied. When the first current is caused to flow, a control voltage that is a voltage for controlling the direct current is generated and output to the DC-DC converter,
If the DC-DC converter has failed, no voltage is applied from the DC-DC converter to the inductor, and the first current does not flow through the shunt resistor, so that the control voltage is not generated. The power supply device according to claim 3. At least two DC-DC converters connected in parallel to the load;
A power supply apparatus comprising: a first current generation unit configured to generate a first current corresponding to a load current that is a current flowing through the load by each DC-DC converter supplying power to the load. A control voltage generation unit that is mounted and provided for one DC-DC converter,
A shunt resistor having a resistance value proportional to the capability of the corresponding DC-DC converter;
An ON state in which a control voltage for controlling the output of the corresponding DC-DC converter is generated by the first current flowing through the shunt resistor, and an OFF state in which the first current does not flow through the shunt resistor. And a relay circuit that switches the switch circuit with
The control voltage generation unit, wherein the relay circuit turns on the switch circuit in conjunction with the operation of the corresponding DC-DC converter.

Images