JP2022063604A - Current control unit and power supply system - Google Patents

Abstract

To provide a current control unit and a power supply system that can prevent the occurrence of an overcurrent in a DC load.SOLUTION: A current control unit 20 is inserted between a voltage control unit 10 and a DC load 50. Based on a DC voltage output from the voltage control unit 10, the current control unit 20 controls a DC current of a DC power output to the DC load 50 so that the DC current becomes a predetermined target current, and thereby outputs the DC power. Based on power from a power supply 40, the voltage control unit 10 controls the DC voltage so that the DC voltage becomes a predetermined target voltage, and thereby outputs the DC voltage.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to current control devices and power supply systems.

Patent Document 1 discloses a power supply device. The power supply device of Patent Document 1 is a switching power supply device, and includes an input unit that receives an input voltage from the outside, a power supply unit, and an output unit. The power supply unit generates a DC voltage from the voltage input through the input unit and outputs it from the output unit.

Japanese Unexamined Patent Publication No. 2020-88942

In the power supply device of Patent Document 1, the power supply unit controls the power supply voltage so that the power supply voltage, which is the output voltage, becomes a specified voltage. Therefore, when the resistance value of the DC load changes during the operation of the DC load, an overcurrent may occur in the DC load.

The present disclosure provides a current control device and a power supply system capable of preventing the occurrence of overcurrent in a DC load.

The current control device of one aspect of the present disclosure is inserted between the voltage control device and the DC load. The current control device outputs DC power by controlling the DC current so that the DC current of the DC power output to the DC load becomes a predetermined target current based on the DC voltage output from the voltage control device. do.

The power supply system of one aspect of the present disclosure includes a voltage control device and at least one current control device. The voltage control device outputs a DC voltage by controlling the DC voltage so that the output DC voltage becomes a predetermined target voltage based on the electric power from the power source. At least one current control device controls the direct current so that the direct current of the direct current output to the direct current load becomes a predetermined target current based on the direct current voltage output from the voltage control device. Output power.

According to the present disclosure, it is possible to prevent the occurrence of overcurrent in a DC load.

It is a block diagram which shows the structural example of the power supply system which concerns on Embodiment 1. FIG. It is a block diagram which shows the structural example of the voltage control apparatus included in the power supply system of FIG. It is a circuit diagram which shows the structural example of the current control device included in the power supply system of FIG. 6 is a graph showing the relationship between current and voltage satisfying the condition that the product of current and voltage is equal to the rated power of the voltage controller of FIG. 2. It is a graph which shows the change of the current with respect to the voltage of the DC load connected to the current control device of FIG. It is a graph which shows the change of the current with respect to the voltage of the DC load directly connected to the voltage control device of FIG. It is a block diagram which shows the structural example of the power supply system which concerns on Embodiment 2.

Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed explanation than necessary may be omitted. For example, detailed explanations of already well-known matters and duplicate explanations for substantially the same configuration may be omitted. This is to avoid unnecessary redundancy of the following description and to facilitate the understanding of those skilled in the art. It should be noted that the inventor (or others) intends to limit the subject matter described in the claims by those skilled in the art by providing the accompanying drawings and the following description in order to fully understand the present disclosure. It is not something to do.

(Embodiment 1)
[1-1. overview]
FIG. 1 is a block diagram showing a configuration example of the power supply system 1 according to the first embodiment. The power supply system 1 supplies DC power to the DC load 50 based on the power from the power source 40.

In FIG. 1, the power supply 40 is, for example, a commercial AC power supply. The power supply 40 is not limited to an AC power source such as a commercial AC power source, and may be a DC power source. Examples of the DC power source include solar cells, fuel cells and storage batteries. The power supply 40 may be a power conditioner that selectively supplies power from an AC power supply and a DC power supply.

In FIG. 1, the DC load 50 operates by DC power. The DC load 50 has a characteristic that the resistance value of the DC load 50 changes when the DC load 50 operates. The DC load 50 is, for example, a laser diode. If the forward voltage of the laser diode is equal to or less than the threshold voltage, almost no current flows through the laser diode. When the forward voltage of the laser diode exceeds the threshold voltage, a large current flows through the laser diode. Therefore, the resistance value of the laser diode when the forward voltage of the laser diode exceeds the threshold voltage is smaller than the resistance value of the laser diode when the forward voltage of the laser diode is equal to or less than the threshold voltage. .. As described above, the laser diode has a characteristic that the resistance value changes during operation. The DC load 50 is not limited to the laser diode and may be a light emitting diode. Further, examples of the DC load 50 include sensors, motors, solenoid valves, and the like.

As shown in FIG. 1, the power supply system 1 includes a voltage control device 10 and current control devices 20-1, ..., 20-N (hereinafter, collectively referred to as reference numerals 20). The voltage control device 10 outputs a DC voltage by controlling the DC voltage so that the output DC voltage becomes a predetermined target voltage based on the power from the power source 40. The current control device 20 controls the DC current so that the DC current of the DC power output to the DC load 50 becomes a predetermined target current based on the DC voltage output from the voltage control device 10. Output power.

Since the power supply system 1 has a current control device 20 interposed between the voltage control device 10 and the DC load 50, it is not a voltage source but a current source for the DC load 50. Therefore, even if the resistance value of the DC load 50 changes during the operation of the DC load 50 and the DC current of the DC power supplied to the DC load 50 changes, the current control device 20 causes the DC current to reach a predetermined target current. The direct current is controlled so as to be. Therefore, the power supply system 1 can reduce the possibility of overcurrent occurring in the DC load 50.

[1-2. detail]
Hereinafter, the power supply system 1 will be described in detail. As shown in FIG. 1, the power supply system 1 includes a voltage control device 10 and a plurality of current control devices 20-1, ..., 20-N. Here, N represents the number of current control devices 20.

[1-2-1. Voltage controller configuration]
In FIG. 1, the voltage control device 10 outputs a DC voltage by controlling the DC voltage so that the output DC voltage becomes a predetermined target voltage based on the power from the power source 40. The voltage control device 10 is a switching power supply for outputting a constant voltage. The voltage control device 10 is attached to an object such as a DIN rail. The connection between the voltage control device 10 and the power supply 40 is not limited to electric wires, but is realized by an appropriate wiring method such as a conductive bar.

FIG. 2 is a block diagram showing a configuration example of the voltage control device 10. As shown in FIG. 2, the voltage control device 10 includes a rectifier circuit 11, a smoothing circuit 12, a switching circuit 13, a rectifier circuit 14, a smoothing circuit 15, a voltage detection circuit 16, and a control circuit 17. ..

The rectifier circuit 11 is configured to include, for example, a diode bridge. The rectifier circuit 11 rectifies the voltage from the power supply 40 and outputs the rectified voltage to the smoothing circuit 12.

The smoothing circuit 12 is configured to include, for example, a smoothing capacitor. The smoothing circuit 12 smoothes the voltage from the rectifier circuit 11 and outputs the smoothed voltage to the switching circuit 13.

The switching circuit 13 includes, for example, a transformer and a switching element. The primary winding of the transformer and the switching element are electrically connected in series between both ends of the smoothing capacitor of the smoothing circuit 12. The secondary winding of the transformer is connected to the rectifier circuit 14. The control circuit 17 switches the voltage from the smoothing circuit 12 by outputting a PWM signal to the switching element of the switching circuit 13, and applies a pulse voltage to the primary winding of the transformer. The secondary winding of the transformer outputs a pulse voltage lower than the pulse voltage input to the primary winding of the transformer to the rectifier circuit 14.

The rectifier circuit 14 is configured to include, for example, a rectifier diode. The rectifier circuit 14 rectifies the pulse voltage from the secondary winding of the transformer of the switching circuit 13, and outputs the rectified voltage to the smoothing circuit 15.

The smoothing circuit 15 is configured to include, for example, a smoothing capacitor. The smoothing circuit 15 smoothes the voltage from the rectifier circuit 14 and outputs a DC voltage.

The voltage detection circuit 16 detects the DC voltage output from the smoothing circuit 15, and outputs a voltage detection signal indicating the detected DC voltage to the control circuit 17.

The control circuit 17 controls the duty ratio of the PWM signal output to the switching element of the switching circuit 13 so that the DC voltage indicated by the voltage detection signal from the voltage detection circuit 16 becomes a predetermined target voltage.

Since the configuration of the voltage control device 10 may be the same as the configuration of a well-known switching power supply or other circuit for generating a constant voltage, detailed description of the voltage control device 10 will be omitted.

[1-2-2. Current controller configuration]
In FIG. 1, a plurality of current control devices 20-1, ..., 20-N are electrically connected in parallel to the voltage control device 10 and receive a DC voltage from the voltage control device 10. Each of the plurality of current control devices 20-1, ..., 20-N is electrically connected to the DC load 50. Each current control device 20 controls the DC current so that the DC current of the DC power output to the DC load 50 becomes a predetermined target current based on the DC voltage output from the voltage control device 10. Outputs DC power. The current control device 20 is a switching power supply for outputting a constant current. The current control device 20 is attached to an object such as a DIN rail. The connection between the current control device 20 and the voltage control device 10 and the DC load 50 is not limited to electric wires, but is realized by an appropriate wiring method such as a conductive bar.

FIG. 3 is a circuit diagram showing a configuration example of the current control device 20. As shown in FIG. 3, the current control device 20 includes a switching circuit 21, a current detection circuit 22, an adjustment circuit 23, and a control circuit 24.

The switching circuit 21 outputs DC power to the DC load 50 based on the DC voltage from the voltage control device 10. The switching circuit 21 is a step-down chopper including a switching element S1, a coil L1 and a diode D1.

The current detection circuit 22 detects the DC current of the DC power output to the DC load 50, and outputs a current detection signal indicating the detected DC current to the control circuit 24. The current detection circuit 22 includes a resistor R1 for current detection and an operational amplifier OP1. The resistor R1 is electrically connected in series with the DC load 50. The non-inverting input terminal and the inverting input terminal of the operational amplifier OP1 are electrically connected to the first end and the second end of the resistor R1 via the resistors R2 and R3, respectively. The non-inverting input terminal of the operational amplifier OP1 is electrically connected to the ground via the resistor R4. The inverting input terminal of the operational amplifier OP1 is electrically connected to the output terminal of the operational amplifier OP1 via the resistor R5. The current detection circuit 22 outputs a voltage corresponding to the current flowing through the resistor R1 as a current detection signal from the output terminal of the operational amplifier OP1.

The adjusting circuit 23 adjusts a predetermined target current of the current control device 20 and outputs a target signal indicating the predetermined target current to the control circuit 24. The adjustment circuit 23 includes a variable resistor VR1. One end of the variable resistor VR1 is electrically connected to the ground, and the other end of the variable resistor VR1 is electrically connected to the internal power supply Vcc via the resistor R6. The variable resistance value output terminal of the variable resistor VR1 is electrically connected to the control circuit 24 via the resistor R7. The variable resistance value of the variable resistor VR1 corresponds to a predetermined target current. By adjusting the variable resistance value of the variable resistor VR1, a predetermined target current is adjusted. The adjustment circuit 23 outputs a voltage corresponding to the variable resistance value of the variable resistor VR1 as a target signal from the variable resistance value output terminal of the variable resistor VR1.

The control circuit 24 controls the switching circuit 21 so that the DC current of the DC power supplied from the current control device 20 to the DC load 50 becomes a predetermined target current adjusted by the adjustment circuit 23. The control circuit 24 includes a drive circuit 241, a comparator CP1, a photocoupler PC1, and a switch S2. The non-inverting input terminal of the comparator CP1 is electrically connected to the variable resistance value terminal of the variable resistor VR1 via the resistor R7. The inverting input terminal of the comparator CP1 is electrically connected to the output terminal of the operational amplifier OP1 of the current detection circuit 22, and receives a current detection signal from the current detection circuit 22. The photodiode PD1 of the photocoupler PC1 is electrically connected to the switch S2. The phototransistor PT1 of the photocoupler PC1 is electrically connected between the non-inverting input terminal of the comparator CP1 and the ground. The switch S2 switches between light emission and non-light emission of the photodiode PD1 according to the manual operation of the switch S2.

The drive circuit 241 outputs a PWM signal to the gate of the switching element S1 via the resistor R8 to drive the switching element S1. When the phototransistor PT1 is off, the non-inverting input terminal of the comparator CP1 receives the target signal from the adjustment circuit 23. The output terminal of the comparator CP1 outputs a voltage corresponding to the difference between the voltage of the target signal from the adjustment circuit 23 and the voltage of the current detection signal from the current detection circuit 22. The drive circuit 241 adjusts the duty ratio of the PWM signal output to the switching element S1 so that the voltage of the output terminal of the comparator CP1 becomes small. In this way, the control circuit 24 controls the switching circuit 21 so that the DC current of the DC power supplied from the switching circuit 21 becomes a predetermined target current. When the phototransistor PT1 is on, the non-inverting input terminal of the comparator CP1 is connected to the ground via the phototransistor PT1, the voltage of the output terminal of the comparator CP1 becomes 0, and the drive circuit 241 does not drive the switching element S1. ..

Next, the rated powers of the plurality of current control devices 20-1, ..., 20-N will be described. In the power supply system 1 of FIG. 1, the rated powers of the plurality of current control devices 20-1, ..., 20-N are set based on the rated power of the voltage control device 10. The total rated power of the plurality of current control devices 20-1, ..., 20-N is equal to or less than the rated power of the voltage control device 10. In an ideal case where there is no power loss in the switching circuit 21 of the current control device 20, the sum of the rated powers of the plurality of current control devices 20-1, ..., 20-N becomes the rated power of the voltage control device 10. The rated voltage and the predetermined target current of the plurality of current control devices 20-1, ..., 20-N can be set so as to match.

In the power supply system 1 configured as described above, the predetermined target current of the current control device 20 can be set to be equal to or less than the maximum rated current of the DC load 50. In this case, the DC load 50 can be prevented from being destroyed.

In the power supply system 1 configured as described above, the predetermined target current of the current control device 20 can be set to be larger than the rated current of the voltage control device 10. In this case, the current control device 20 can output a current larger than the current output by the voltage control device 10 to the DC load 50 to the DC load 50. This prevents the current from being insufficient when the DC load 50 is started. Therefore, it is possible to contribute to the improvement of the start-up of the DC load 50 and to improve the stability of the DC load 50 at the start of operation. When the power supply system 1 includes a plurality of current control devices 20, the plurality of current control devices 20 are provided so that at least one predetermined target current of the plurality of current control devices 20 is larger than the rated current of the voltage control device 10. At least one predetermined target current can be set.

In the power supply system 1 configured as described above, the rated voltage of the current control device 20 can set the DC load 50 to be equal to or higher than the operating voltage. In this case, the stability of the DC load 50 at the start of operation can be improved.

Next, an example of a predetermined target current and rated voltage of each of the plurality of current control devices 20-1, ..., 20-N will be described with reference to FIG. FIG. 4 is a graph showing the relationship between current and voltage satisfying the condition that the product of current and voltage becomes equal to the rated power of the voltage control device 10. In FIG. 4, I ₁₀ indicates the rated current of the voltage control device 10, and V ₁₀ indicates a predetermined target voltage of the voltage control device 10. For example, I ₁₀ is 10A, V ₁₀ is 24V, and the rated power of the voltage controller 10 is 240W.

For example, the rated voltages of the plurality of current control devices 20-1, ..., 20-N can be set so that the rated voltages of the plurality of current control devices 20-1, ..., 20-N are equal to each other. When each of the rated voltages of the plurality of current control devices 20-1, ..., 20-N is V ₂₀ , the sum of the predetermined target currents of the plurality of current control devices 20-1, ..., 20-N is I. If it is ₂₀ , V ₂₀ × I ₂₀ = V ₁₀ × I ₁₀ . When the operating voltage of the DC load 50 is 3V, if V ₂₀ is 3V, I ₂₀ is 80A. When the number N of the current control devices 20 is 5, all of the predetermined target currents of the five current control devices 20-1, 20-2, 20-3, 20-4, 20-5 are set by the voltage control device 10. Set to the rated current or higher. The direct currents of the five current control devices 20-1, 20-2, 20-3, 20-4, 20-5 are, for example, 20A, 18A, 16A, 14A, 12A. Five current control devices 5 current control devices so that at least one predetermined target current of the five current control devices 20-1, 20-2, 20-3, 20-4, 20-5 is larger than the rated current of the voltage control device 10. At least one predetermined target current of 20-1, 20-2, 20-3, 20-4, 20-5 may be set.

For example, the predetermined target currents of the plurality of current control devices 20-1, ..., 20-N can be set so that the predetermined target currents of the plurality of current control devices 20-1, ..., 20-N are equal to each other. When each of the predetermined target currents of the plurality of current control devices 20-1, ..., ₂₀ -N is I20, the total rated voltage of the plurality of current control devices 20-1, ..., 20-N is V. If it is ₂₀ , V ₂₀ × I ₂₀ = V ₁₀ × I ₁₀ . If I ₂₀ is 12A, then V ₂₀ is 20V. When the number N of the current control devices 20 is 3, the rated voltages of the three current control devices 20-1, 20-2, and 20-3 are, for example, 10V, 7V, and 3V, respectively.

For example, the predetermined target currents of the plurality of current control devices 20-1, ..., 20-N are equal to each other, and the rated voltages of the plurality of current control devices 20-1, ..., 20-N are equal to each other. , A predetermined target current and rated voltage of a plurality of current control devices 20-1, ..., 20-N can be set. Assuming that the predetermined target current of the current control device 20 is I ₃₀ and the rated voltage is V ₃₀ , N × V ₃₀ × I ₃₀ = V ₁₀ × I ₁₀ . When the number N of the current control device 20 is 5, for example, V ₃₀ is 3V and I ₃₀ is 16A.

For example, the predetermined target currents of the plurality of current control devices 20-1, ..., 20-N are different from each other, and the rated voltages of the plurality of current control devices 20-1, ..., 20-N are different from each other. Predetermined target currents and rated voltages of a plurality of current control devices 20-1, ..., 20-N can be set. When the number N of the current control device 20 is 2, the predetermined target current of the current control device 20-1 is I ₄₁ , the rated voltage is V ₄₁ , and the predetermined target current of the current control device 20-2 is I ₄₂ , Assuming that the rated voltage is V ₄₂ , V ₄₁ × I ₄₁ + V ₄₂ × I ₄₂ = V ₁₀ × I ₁₀ . For example, I ₄₁ is 24A, V ₄₁ is 5V, I ₄₂ is 20A, and V ₄₂ is 6V.

[1-2-3. Performance evaluation]
In order to confirm that the power supply system 1 can prevent the occurrence of overcurrent in the DC load 50, the relationship between the voltage applied to the DC load 50 and the current flowing through the DC load 50 was investigated. FIG. 5 is a graph showing changes in the current flowing through the DC load 50 with respect to the voltage applied to the DC load 50 when the DC load 50 is connected to the voltage control device 10 via the current control device 20. FIG. 6 is a graph showing changes in the current flowing through the DC load 50 with respect to the voltage applied to the DC load 50 when the DC load 50 is connected to the voltage control device 10 instead of the current control device 20. In FIGS. 5 and 6, _Vth indicates the threshold voltage of the DC load 50, and _Ir indicates the maximum rated current of the DC load 50.

As can be seen from FIGS. 5 and 6, when the voltage applied to the DC load 50 is equal to or less than the threshold voltage _Vth , the DC load 50 is in a state in which almost no current flows through the DC load 50. This state is close to the state in which the DC load 50 is not connected to the voltage control device 10 or the current control device 20.

On the other hand, when the voltage applied to the DC load 50 exceeds the threshold voltage _Vth , the current flowing through the DC load 50 increases. In the case of FIG. 6, the voltage control device 10 controls the DC voltage output to the DC load 50, but does not control the current itself flowing through the DC load 50. Therefore, the current flowing through the DC load 50 increases beyond the maximum rated current _Ir of the DC load 50. In the case of FIG. 6, the load due to the DC load 50 decreases when the voltage applied to the DC load 50 exceeds the threshold voltage _Vth , and then increases. As described above, when the DC load 50 is a laser diode, a light emitting diode, or the like and has a threshold voltage _Vth , the voltage control device 10 is directly connected to the DC load 50 and the DC load 50 is operated by the voltage control device 10. , A large current flows at the moment when the voltage applied to the DC load 50 exceeds the threshold voltage _Vth . This may damage the DC load 50.

In the case of FIG. 5, the current control device 20 controls the DC current so that the DC current of the DC power supplied to the DC load 50 becomes a predetermined target current _Ic . Therefore, the current flowing through the DC load 50 does not exceed the maximum rated current _Ir . In order to prevent the DC load 50 from being damaged when the DC load 50 is a laser diode, a light emitting diode, or the like and has a threshold voltage _Vth , DC power is supplied from the current control device 20 as a current source to the DC load 50. It will be necessary to supply. By supplying DC power from the current control device 20 as a current source to the DC load 50, it is possible to prevent the occurrence of overcurrent in the DC load 50.

As is clear from the graphs shown in FIGS. 5 and 6, it was confirmed that the power supply system 1 can prevent the occurrence of overcurrent in the DC load 50.

[1-3. Effect, etc.]
As described above, in the present embodiment, the power supply system 1 includes a voltage control device 10 and a plurality of current control devices 20. The voltage control device 10 outputs a DC voltage by controlling the DC voltage so that the output DC voltage becomes a predetermined target voltage based on the power from the power source 40. Each of the plurality of current control devices 20 controls the DC current so that the DC current of the DC power output to the DC load 50 becomes a predetermined target current based on the DC voltage output from the voltage control device 10. As a result, DC power is output.

As shown in FIG. 1, in the power supply system 1, the current control device 20 is inserted between the voltage control device 10 and the DC load 50. Therefore, even if the resistance value of the DC load 50 changes during the operation of the DC load 50 and the DC current of the DC power supplied to the DC load 50 changes, the current control device 20 causes the DC current to reach a predetermined target current. The direct current is controlled so as to be. As a result, the power supply system 1 can prevent the occurrence of an overcurrent in the DC load 50. In particular, even when the voltage control device 10 is already installed, the current control device 20 is retrofitted to the voltage control device 10 so that the current control device 20 is inserted between the voltage control device 10 and the DC load 50. Thereby, it is possible to construct the power supply system 1. As described above, in the power supply system 1, the current control device 20 can be simply externally attached to the voltage control device 10. It is also possible to prepare one voltage control device 10 and use a large number of current control devices 20. In this case, the plurality of current control devices 20 can distribute the current to the plurality of DC loads 50.

Further, in the present embodiment, the power supply system 1 includes a plurality of current control devices 20-1, ..., 20-N, and can supply DC power from the voltage control device 10 to the plurality of DC loads 50. In particular, each of the plurality of current control devices 20-1, ..., 20-N controls the DC current so that the DC current of the DC power output to the DC load 50 becomes a predetermined target current. Even if any of the plurality of DC loads 50 is short-circuited, the current flowing through the short-circuited DC load 50 does not exceed a predetermined target current. Therefore, it is possible to prevent a short circuit of any one of the plurality of DC loads 50 from affecting the remaining DC loads 50. Even if any of the plurality of DC loads 50 is short-circuited, it is possible to prevent the remaining DC loads 50 from being damaged or broken. Therefore, the operation of the power supply system 1 can be normally terminated for the replacement of the short-circuited DC load 50 or the like.

Further, in the present embodiment, the DC load 50 has a characteristic that the resistance value of the DC load 50 changes when the DC load 50 operates. According to this configuration, it is possible to prevent the occurrence of an overcurrent in a DC load 50 having a characteristic that the resistance value changes during operation.

Further, in the present embodiment, the DC load 50 is a light emitting diode or a laser diode. According to this configuration, it is possible to prevent the generation of overcurrent in the light emitting diode or the laser diode.

Further, in the present embodiment, the predetermined target current of the current control device 20 is equal to or less than the maximum rated current of the DC load 50. According to this configuration, it is possible to prevent the DC load 50 from being destroyed.

Further, in the present embodiment, the rated voltage of the current control device 20 is equal to or lower than the DC voltage output from the voltage control device 10. In other words, the rated voltage of the current control device 20 is equal to or lower than the predetermined target voltage of the voltage control device 10. Further, the rated voltage of the current control device 20 is equal to or higher than the operating voltage of the DC load 50. According to this configuration, the stability of the DC load 50 at the start of operation can be improved.

Further, in the present embodiment, the rated power of the current control device 20 is equal to or less than the rated power of the voltage control device 10. The predetermined target current of the current control device 20 is larger than the rated current of the voltage control device 10. According to this configuration, the stability of the DC load 50 at the start of operation can be improved.

Further, in the present embodiment, the power supply system 1 includes a plurality of current control devices 20. The total rated power of the plurality of current control devices 20 is equal to or less than the rated power of the voltage control device 10. The at least one predetermined target current of the plurality of current control devices 20 is larger than the rated current of the voltage control device 10. According to this configuration, the stability of the DC load 50 at the start of operation can be improved.

(Embodiment 2)
FIG. 7 is a block diagram showing a configuration example of the power supply system 1A of the second embodiment. The power supply system 1A includes a voltage control device 10, a plurality of current control devices 20-1, 20-2, 20-3, ..., 20-N, and a distribution device 30.

In FIG. 7, the distribution device 30 distributes the DC voltage from the voltage control device 10 to the plurality of current control devices 20. The distribution device 30 includes an input terminal electrically connected to the voltage control device 10 and a plurality of output terminals electrically connected to each of the plurality of current control devices 20. The distribution device 30 outputs the DC voltage from the voltage control device 10 received at the input terminal to the plurality of current control devices 20 from each of the plurality of output terminals.

In FIG. 7, two current control devices 20-1, 20-2 and a distribution device 30 are directly connected to the voltage control device 10, and the remaining current control devices 20-3, ..., 20-N are connected to the distribution device 30. Is connected. The current control device 20 does not necessarily have to be directly connected to the voltage control device 10, but may be indirectly connected to the voltage control device 10 via the distribution device 30.

Since the distribution device 30 may have a well-known configuration, detailed description of the distribution device 30 will be omitted. The distribution device 30 is attached to an object such as a DIN rail. The connection between the distribution device 30 and the voltage control device 10 and the current control device 20 is not limited to electric wires, but is realized by an appropriate wiring method such as a conductive bar.

As described above, in the present embodiment, the power supply system 1A includes the distribution device 30, and the distribution device 30 distributes the DC voltage from the voltage control device 10 to the plurality of current control devices 20. According to the distribution device 30, a plurality of current control devices 20 can be connected in parallel to one output terminal of the voltage control device 10. By using the distribution device 30, the number of current control devices 20 that can be connected to the voltage control device 10 can be increased. According to this configuration, the degree of freedom of wiring for connecting the plurality of current control devices 20 to the voltage control device 10 can be improved.

(Modification example)
The embodiments of the present disclosure are not limited to the first and second embodiments. If the subject of the present disclosure can be achieved, various modifications of the first and second embodiments can be made according to the design and the like. The modified examples of the first and second embodiments are listed below. The modifications described below can be applied in combination as appropriate.

In one modification, the number of voltage control devices 10, the number of current control devices 20, and the number of distribution devices 30 are not particularly limited. The power supply system 1 may include at least one voltage control device 10 and at least one current control device 20.

When the power supply system 1 includes one voltage control device 10 and one current control device 20, the rated power of the current control device 20 is set to be equal to or lower than the rated power of the voltage control device 10. Ideally, there is no power loss in the switching circuit 21 of the current control device 20, and the rated power of the current control device 20 is set so that the rated power of the current control device 20 matches the rated power of the voltage control device 10. can.

With reference to FIG. 4, if the predetermined target current of the current control device 20 is I ₂₀ and the rated voltage of the current control device 20 is V ₂₀ , then V ₂₀ × I ₂₀ ≦ V ₁₀ × I ₁₀ is established. V ₂₀ and I ₂₀ can be set. When the operating voltage of the DC load 50 is 3V, V ₂₀ can be set to, for example, 3V, and I ₂₀ can be set to, for example, 20A to 80A.

In this case, the predetermined target current of the current control device 20 can be set to 2 to 8 times the rated current of the voltage control device 10. In this way, the current control device 20 can output a current larger than the current output by the voltage control device 10 to the DC load 50 to the DC load 50. This makes it possible to prevent the current from being insufficient when the DC load 50 is started. Therefore, it is possible to contribute to the improvement of the start-up of the DC load 50 and to improve the stability of the DC load 50 at the start of operation.

In one modification, the voltage control device 10 may be connectable to a plurality of power sources 40 and may receive power from all or part of the plurality of power sources 40. The voltage control device 10 may include a noise filter, an inrush current limiting circuit, a harmonic current suppression circuit, an overvoltage protection circuit, and an overcurrent protection circuit, if necessary. Since the noise filter, the inrush current limiting circuit, the harmonic current suppression circuit, the overvoltage protection circuit, and the overcurrent protection circuit may have conventionally known configurations, detailed description thereof will be omitted.

In one modification, the current control device 20 may receive a DC voltage from any one of the one or more voltage control devices 10 and the one or more distribution devices 30. The current control device 20 may supply DC power to each of the plurality of DC loads 50. The current control device 20 does not necessarily have to have the adjustment circuit 23. The circuit configuration of the switching circuit 21 and the current detection circuit 22 of the current control device 20 is not limited to the circuit configuration shown in FIG. 3, and may be a well-known circuit configuration.

(Aspect)
As will be apparent from embodiments 1 and 2 and modifications, the present disclosure includes the following aspects. In the following, reference numerals are given in parentheses only for clarifying the correspondence with the first and second embodiments.

The first aspect is a current control device (20) inserted between the voltage control device (10) and the DC load (50). The current control device (20) is based on the DC voltage output from the voltage control device (10) so that the DC current of the DC power output to the DC load (50) becomes a predetermined target current. By controlling the direct current, it is configured to output direct current power. According to this aspect, overcurrent in the DC load (50) can be prevented.

The second aspect is the current control device (20) based on the first aspect. In the second aspect, the voltage control device (10) controls the DC voltage so that the DC voltage becomes a predetermined target voltage based on the electric power from the power source (40), thereby causing the DC voltage. Is configured to output. According to this aspect, overcurrent in the DC load (50) can be prevented.

The third aspect is the current control device (20) based on the first or second aspect. In the third aspect, the DC load (50) has a characteristic that the resistance value of the DC load (50) changes when the DC load (50) operates. According to this aspect, it is possible to prevent the occurrence of an overcurrent in a DC load (50) having a characteristic that the resistance value changes during operation.

The fourth aspect is the current control device (20) based on the third aspect. In the fourth aspect, the DC load (50) is a light emitting diode or a laser diode. According to this aspect, it is possible to prevent the generation of overcurrent in the light emitting diode or the laser diode.

A fifth aspect is a current control device (20) based on any one of the first to fourth aspects. In the fifth aspect, the predetermined target current is equal to or less than the maximum rated current of the DC load (50). According to this aspect, the destruction of the DC load (50) can be prevented.

The sixth aspect is the current control device (20) based on any one of the first to fifth aspects. In the sixth aspect, the rated voltage of the current control device (20) is equal to or lower than the DC voltage of the voltage control device (10) and equal to or higher than the operating voltage of the DC load (50). According to this aspect, the stability of the DC load (50) at the start of operation can be improved.

A seventh aspect is a current control device (20) based on any one of the first to sixth aspects. In the seventh aspect, the rated power of the current control device (20) is equal to or less than the rated power of the voltage control device (10). The predetermined target current of the current control device (20) is larger than the rated current of the voltage control device (10). According to this aspect, the stability of the DC load (50) at the start of operation can be improved.

Eighth aspect is a power supply system (1; 1A), comprising a voltage control device (10) and at least one current control device (20). The voltage control device (10) outputs the DC voltage by controlling the DC voltage so that the output DC voltage becomes a predetermined target voltage based on the electric power from the power source (40). It is composed of. In the at least one current control device (20), the DC current of the DC power output to the DC load (50) becomes a predetermined target current based on the DC voltage output from the voltage control device (10). By controlling the DC current so as to be, the DC power is output. According to this aspect, it is possible to prevent the occurrence of an overcurrent in the DC load (50).

A ninth aspect is a power supply system (1; 1A) based on the eighth aspect. In the ninth aspect, the DC load (50) has a characteristic that the resistance value of the DC load (50) changes when the DC load (50) is operated. According to this aspect, it is possible to prevent the occurrence of an overcurrent in a DC load (50) having a characteristic that the resistance value changes during operation.

A tenth aspect is a power supply system (1; 1A) based on the ninth aspect. In a tenth aspect, the DC load (50) is a light emitting diode or a laser diode. According to this aspect, it is possible to prevent the generation of overcurrent in the light emitting diode or the laser diode.

The eleventh aspect is a power supply system (1; 1A) based on any one of the eighth to tenth aspects. In the eleventh aspect, the predetermined target current is equal to or less than the maximum rated current of the DC load (50). According to this aspect, the destruction of the DC load (50) can be prevented.

A twelfth aspect is a power supply system (1; 1A) based on any one of the eighth to eleventh aspects. In the twelfth aspect, the rated voltage of the at least one current control device (20) is equal to or lower than the predetermined target voltage and equal to or higher than the operating voltage of the DC load (50). According to this aspect, the stability of the DC load (50) at the start of operation can be improved.

A thirteenth aspect is a power supply system (1; 1A) based on any one of the eighth to twelfth aspects. In a thirteenth aspect, the power supply system (1; 1A) comprises one said current control device (20). The rated power of the current control device (20) is equal to or lower than the rated power of the voltage control device (10). The predetermined target current of the current control device (20) is larger than the rated current of the voltage control device (10). According to this aspect, the stability of the DC load (50) at the start of operation can be improved.

A fourteenth aspect is a power supply system (1; 1A) based on any one of the eighth to twelfth aspects. In a fourteenth aspect, the power supply system (1; 1A) comprises a plurality of the current control devices (20). The total rated power of the plurality of current control devices (20) is equal to or less than the rated power of the voltage control device (10). The predetermined target current of at least one of the plurality of current control devices (20) is larger than the rated current of the voltage control device (10). According to this aspect, the stability of the DC load (50) at the start of operation can be improved.

As described above, an embodiment has been described as an example of the technique in the present disclosure. To that end, an attached drawing and a detailed description are provided. Therefore, among the components described in the attached drawings and the detailed description, not only the components essential for problem solving but also the components not essential for problem solving in order to illustrate the above technique. Can also be included. Therefore, the fact that those non-essential components are described in the accompanying drawings or detailed description should not immediately determine that those non-essential components are essential. Further, since the above-described embodiment is for exemplifying the technique in the present disclosure, various changes, replacements, additions, omissions, etc. can be made within the scope of claims or the equivalent thereof.

The present disclosure is applicable to current control devices and power supply systems. Specifically, the present disclosure is applicable to a current control device and a power supply system for supplying electric power to a DC load.

1, 1A power supply system 10 Voltage control device 20 Current control device 40 Power supply 50 DC load

Claims (14)

A current control device inserted between the voltage control device and the DC load.
The current control device controls the DC current so that the DC current of the DC power output to the DC load becomes a predetermined target current based on the DC voltage output from the voltage control device. Output DC power,
Current controller. The voltage control device outputs the DC voltage by controlling the DC voltage so that the DC voltage becomes a predetermined target voltage based on the electric power from the power source.
The current control device according to claim 1. The DC load has a characteristic that the resistance value of the DC load changes when the DC load is operated.
The current control device according to claim 1 or 2. The DC load is a light emitting diode or a laser diode.
The current control device according to claim 3. The predetermined target current is equal to or less than the maximum rated current of the DC load.
The current control device according to any one of claims 1 to 4. The rated voltage of the current control device is equal to or lower than the DC voltage of the voltage control device and equal to or higher than the operating voltage of the DC load.
The current control device according to any one of claims 1 to 5. The rated power of the current control device is equal to or lower than the rated power of the voltage control device.
The predetermined target current of the current control device is larger than the rated current of the voltage control device.
The current control device according to any one of claims 1 to 6. A voltage control device that outputs the DC voltage by controlling the DC voltage so that the output DC voltage becomes a predetermined target voltage based on the power from the power source.
The DC power is output by controlling the DC current so that the DC current of the DC power output to the DC load becomes a predetermined target current based on the DC voltage output from the voltage control device. With at least one current controller,
To prepare
Power system. The DC load has a characteristic that the resistance value of the DC load changes when the DC load is operated.
The power supply system according to claim 8. The DC load is a light emitting diode or a laser diode.
The power supply system according to claim 9. The predetermined target current is equal to or less than the maximum rated current of the DC load.
The power supply system according to any one of claims 8 to 10. The rated voltage of the at least one current control device is equal to or lower than the predetermined target voltage and equal to or higher than the operating voltage of the DC load.
The power supply system according to any one of claims 8 to 11. Equipped with one of the current control devices,
The rated power of the current control device is equal to or lower than the rated power of the voltage control device.
The predetermined target current of the current control device is larger than the rated current of the voltage control device.
The power supply system according to any one of claims 8 to 12. Equipped with the plurality of current control devices,
The total rated power of the plurality of current control devices is equal to or less than the rated power of the voltage control device.
The predetermined target current of at least one of the plurality of current control devices is larger than the rated current of the voltage control device.
The power supply system according to any one of claims 8 to 12.

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