Power supply device

Abstract

To provide a power supply device that can suppress heat generation.SOLUTION: A power supply device (1a) comprises: a power supply input circuit that includes an insulation transformer (TR) including a primary wiring (TR1) and a secondary wiring (TR2A) insulated from the primary wiring, and an AC power supply (PS) which has a variable output voltage and which excites the primary wiring with the output voltage; a power supply output circuit (2aA) that is connected to the secondary wiring, and that converts an AC voltage input from the secondary wiring by the excitation of the primary wiring to a DC voltage and outputs it to a load; and a voltage control unit (10) that controls the output voltage of the AC power supply and the DC voltage output from the power supply output circuit to the load.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a power supply device. [Background technology]

[0002] Conventionally, there is known a power supply device that converts the AC voltage of an AC commercial power supply into a DC voltage and applies the DC voltage to a load (see Patent Document 1). This power supply device rectifies and smoothes the AC voltage induced in the secondary winding of a power transformer by the AC voltage supplied from the commercial power supply to the primary winding of the power transformer, and adjusts the DC voltage applied to the load with a regulator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 06-209573 Summary of the Invention [Problem to be solved by the invention]

[0004] In general, commercial power sources are expected to fluctuate in voltage within the range of -85 V to +115 V. For this reason, the power supply device described in Patent Document 1 has a problem that if the power transformer is configured to maintain the DC voltage applied to the load even when the voltage supplied to the primary winding of the power transformer is low, when the voltage supplied to the primary winding is high, the potential difference when adjusting with the regulator becomes larger than when the voltage supplied to the primary winding is low, and the power supply device is likely to generate heat.

[0005] The present disclosure is devised to solve the above-mentioned problems, and has an object to provide a power supply device capable of suppressing heat generation. [Means for solving the problem]

[0006] The power supply device according to the present disclosure is characterized by comprising: a power supply input circuit having an isolation transformer having a primary winding and a secondary winding insulated from the primary winding; an AC power supply with a variable output voltage that excites the primary winding with the output voltage; a power supply output circuit connected to the secondary winding and converting the AC voltage input from the secondary winding by exciting the primary winding into a DC voltage and outputting it to a load; and a voltage control unit that controls the output voltage of the AC power supply and the DC voltage output from the power supply output circuit to the load. Effect of the Invention

[0007] According to the present disclosure, the output voltage of the AC power supply that excites the primary winding of the isolation transformer is controlled by the voltage control unit, thereby making it possible to suppress heat generation when the AC voltage from the secondary winding of the isolation transformer is converted into a DC voltage to be applied to a load. [Brief description of the drawings]

[0008] [Figure 1] 1 is a functional block diagram showing an overall configuration of a power supply device according to a first embodiment. [Diagram 2] FIG. 4 is a functional block diagram showing an overall configuration of a power supply device according to a modification of the first embodiment. [Diagram 3] FIG. 11 is a functional block diagram showing an overall configuration of a power supply device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Embodiment 1 (1) Detailed description of the configuration Fig. 1 is a functional block diagram showing the overall configuration of a power supply device 1a according to a first embodiment. As shown in Fig. 1, the power supply device 1a includes an AC power supply PS, an insulating transformer TR, a plurality of power supply output circuits 2aA, 2aB, ..., 2aN, and a higher-level control system 10, and converts, for example, an AC voltage from a commercial AC power supply into a DC voltage and outputs it to a load such as an electrical appliance (not shown). In the first embodiment, the AC power supply PS and the insulating transformer TR form a power supply input circuit. In the present disclosure, N is any natural number equal to or greater than 2.

[0010] The AC power supply PS outputs AC to the isolation transformer TR. More specifically, the AC power supply PS is a variable power supply that outputs a sine wave AC with a higher frequency than the commercial AC power supply to the isolation transformer TR by changing the AC frequency and AC voltage from the commercial AC power supply.

[0011] The isolation transformer TR obtains a voltage for generating an output DC voltage Vdc from the AC power supply PS to be output to a load. The isolation transformer TR has a primary winding TR1 connected to the AC power supply PS, and a plurality of secondary windings TR2A, TR2B, ..., TR2N. The plurality of secondary windings TR2A to TR2N are connected to the power supply output circuits 2aA to 2aN, respectively.

[0012] The power output circuit 2aA has a rectifier diode bridge 11A, a smoothing capacitor 12A, and a control circuit unit 13A, and the rectifier diode bridge 11A and the smoothing capacitor 12A form a rectifier smoothing circuit. The rectifier smoothing circuit has a secondary winding TR2A connected to its input side and a control circuit unit 13A connected to its output side. The control circuit unit 13A has a microcomputer control unit 14A and a regulator circuit 15A. The regulator circuit 15A controls the output DC voltage Vdc. The control circuit unit 13A is supplied with a current for driving the microcomputer control unit 14A and the regulator circuit 15A from a DC power source (not shown).

[0013] The upper control system 10 as a voltage control unit has a function of controlling the entire power supply device 1a and a function of monitoring the operating state of the power supply device 1a. The upper control system 10 is connected to each microcomputer control unit of the power supply output circuits 2aA to 2aN. Specifically, the upper control system 10 is connected to the power supply output circuit 2aA by a set voltage command signal communication line and a communication line. The set voltage command signal communication line transmits a set voltage command signal SVRefA from the upper control system 10 to the power supply output circuit 2aA. The communication line transmits device operation information collected by the microcomputer control unit 14A to the upper control system 10 as a monitor signal SMoA. For example, the device operation information transmitted to the upper control system 10 by the communication line includes information on the output DC voltage Vdc applied to the load, the output DC current If applied to the load, and the temperature of the regulator circuit 15A. The upper control system 10 is also connected to the AC power supply PS by a signal line. The signal line transmits an AC power supply output command value SVPS for controlling the output power of the AC power supply PS from the upper control system 10 to the AC power supply PS.

[0014] The microcomputer control unit 14A is connected to wiring for detecting the positive DC voltage V+, the negative DC voltage V-, and the output DC voltage Vdc output to the load from the rectifying and smoothing circuit. The microcomputer control unit 14A also has an amplifier (not shown) for driving and controlling the control elements 16n and 16p of the regulator circuit 15A. The amplifier monitors and compares the set voltage command signal SVRefA from the upper control system 10, the value of the detected output DC voltage Vdc, and the DC voltages V+ and V- input to the regulator circuit 15A, and drives and controls the control elements 16n and 16p of the regulator circuit 15A to stabilize the output DC voltage Vdc. The microcomputer control unit 14A monitors device operation information such as the voltage and current applied to the load and the temperature of the regulator circuit, and sequentially transmits the information to the upper control system 10 as a monitor signal SMoA.

[0015] The power output circuit 2B has a rectifier diode bridge 11B, a smoothing capacitor 12B, and a control circuit unit 13B, and the control circuit unit 13B has a microcomputer control unit 14A and a regulator circuit 15A. Note that the power output circuits 2aA to 2aN have the same configuration, so illustrations and descriptions of the power output circuits 2aB to 2aN will be partially omitted.

[0016] The operation of the power supply output circuit 2aA will be described below. In order to obtain the output DC voltage Vdc, the AC power supply PS receives an AC power supply output command value SVPS from the upper control system 10 and applies a voltage corresponding to the AC power supply output command value SVPS to the primary winding TR1 of the insulating transformer TR. When a voltage is applied to the primary winding TR1, an AC current corresponding to the turn ratio of the primary winding TR1 and the secondary winding TR2A is output from the secondary winding TR2A of the insulating transformer TR. The AC current output from the secondary winding TR2A is rectified and smoothed by a rectifying and smoothing circuit composed of a rectifying diode bridge 11A and a smoothing capacitor 12A, converted into a DC current, and input to the control elements 16n and 16p of the regulator circuit 15A.

[0017] For example, regulator circuit 15A is formed as a complementary circuit in which control element 16n has an n-type MOSFET (hereinafter referred to as "nMos") which is a Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET), and control element 16p has a p-type MOSFET (hereinafter referred to as "pMos"). nMos is connected to the V+ side of a rectified and smoothed DC power supply, pMos is connected to the V- side of the DC power supply, and a DC voltage is output to a load from the connection midpoint between nMos and pMos.

[0018] Each MOSFET of the control elements 16n, 16p is configured to receive a control drive command from the microcomputer control unit 14A at its respective gate input G, and to control and stabilize the output DC voltage Vdc to the control command voltage while sinking or sourcing the current applied to the load side. Note that the operation of the power output circuits 2aB to 2aN is similar to that of the power output circuit 2aA, and therefore a description thereof will be omitted. Note that, when the current applied to the load is large, a regulator circuit (not shown) is provided in parallel. This also applies to the second embodiment described later.

[0019] On the other hand, the AC power source PS, which is the power source of the insulating transformer TR, is a power source that applies AC to the primary winding TR1 of the insulating transformer TR, and the output command value of the applied AC includes a frequency value and a voltage value. The upper control system 10 transmits a command value to the AC power source PS to obtain a stable output DC voltage Vdc by suppressing heat loss when the control elements 16n, 16p of the regulator circuit 15A perform voltage control, based on the output voltage value applied to the load and the operation information of the device obtained according to the load situation. The AC frequency command value is about 400 to 500 Hz, taking into account the reactance of the power input circuit.

[0020] Fig. 2 is a functional block diagram showing the overall configuration of a power supply device 1b according to a modification of the first embodiment. As shown in Fig. 2, the power supply device 1b includes an AC power supply PS, an insulating transformer TR, a plurality of power supply output circuits 2bA, 2bB, ..., 2bN, and a higher-level control system 10, and the power supply output circuit 2bA has a switch SW1A. A microcomputer control unit 14A of the power supply device 1b monitors the output DC voltage Vdc and output DC current If applied to the load, and the temperature and detects abnormalities of the regulator circuit 15A. When the microcomputer control unit 14A of the power supply device 1b detects an abnormality such as an overcurrent, an overvoltage, or a temperature abnormality, it outputs an abnormality shutoff signal SEMS to the switch SW1A and shuts off the switch SW1A of the system. In other words, when the microcomputer control unit 14A of the power supply device 1b detects an abnormality such as a current exceeding a preset threshold, a voltage exceeding a preset threshold, or a temperature exceeding a preset threshold, the microcomputer control unit 14A outputs an abnormality shutoff signal SEMS to the switch SW1A, shutting off the switch SW1A of the corresponding system, thereby shutting off the output of the DC voltage to the load. Note that, since the control circuit unit 13A is supplied with a DC current through a path different from that of the switch SW1A, shutting off the switch SW1A does not affect the operation of the control circuit unit 13A. In addition, such a microcomputer control unit 14A constitutes a shutoff unit that shuts off the output of the DC voltage to the load when the difference between the preset voltage and the DC voltage output to the load exceeds a preset threshold. In addition, the microcomputer control unit 14A only needs to have a function of cutting off the output of DC voltage to the load by some means when it detects at least one of a current exceeding a predetermined threshold, a voltage exceeding a predetermined threshold, and a temperature exceeding a predetermined threshold.For example, the microcomputer control unit may be configured to output an abnormality cut-off signal to a switch (not shown) arranged between the power supply device and the load, thereby activating the switch and cutting off the output of DC voltage to the load. Also, for example, the microcomputer control unit may be configured to cut off the output of DC voltage to the load by cutting off a circuit at a specific portion of the power supply input circuit when it detects any one of the current, voltage, and temperature exceeding a threshold value, or may be configured to cut off the output of DC voltage to the load by cutting off a circuit at a specific portion of the power supply output circuit when it detects any one of the current, voltage, and temperature exceeding a threshold value. Also, the microcomputer control unit may be configured to cut off the output of DC voltage to the load by cutting off a circuit connected to a primary winding of the isolation transformer when it detects any one of the current, voltage, and temperature exceeding a threshold value, or may be configured to cut off the output of DC voltage to the load by cutting off a circuit connected to a secondary winding of the isolation transformer.

[0021] The microcomputer control unit 14A is not limited to being configured to directly monitor the output DC voltage Vdc and output DC current If applied to the load, and the temperature of the regulator circuit 15A. For example, the microcomputer control unit 14A may be configured to indirectly monitor the output DC voltage Vdc and output DC current If applied to the load by monitoring the voltage and current of a specific portion in the power output circuit 2cA, or may be configured to indirectly monitor the temperature of the regulator circuit 15A by monitoring the temperature of a specific portion of the power supply device or the air temperature at a specific position.

[0022] Furthermore, the power supply output circuit 2bA may be configured to notify the occurrence of an abnormality in the power supply output circuit 2bA of the system when the power supply output circuit 2bA detects an abnormality in the microcomputer control unit 14A and shuts off a specific system with the switch SW1A, by displaying the abnormality in the corresponding system on a display unit (not shown) such as a liquid crystal display device or an LED in the upper control system 10. The microcomputer control unit 14A constitutes a notifying unit that notifies when the difference between a preset voltage and the DC voltage output to the load exceeds a preset threshold value.

[0023] The power output circuit 2bB has a switch SW1B. Note that the configurations of the power output circuits 2bB to 2bN are similar to that of the power output circuit 2bA, and therefore a description thereof will be omitted.

[0024] (2) Key points and features of the implementation example As described above, the power supply devices 1a and 1b according to the first embodiment of the present disclosure control the output voltage of the AC power supply PS that excites the primary winding TR1 of the insulating transformer TR by the upper control system 10, and therefore can suppress heat generation when converting the AC voltage from the secondary windings TR2A to TR2N of the insulating transformer into a DC voltage to be applied to a load. For example, the power supply devices 1a and 1b are configured to apply an AC power supply having a frequency higher than that of a commercial AC power supply to the primary winding TR1 of the insulating transformer TR, and convert the AC excited in the multiple secondary windings TR2A to TR2N into DC in the respective connected power output circuits 2aA to 2aN and 2bA to 2bN. The size of the insulating transformer TR can be reduced as the frequency increases due to the magnetic flux density. Therefore, the power supply devices 1a and 1b can be made smaller than before.

[0025] Furthermore, the power supply units 1a, 1b are equipped with a higher-level control system 10, and the microcomputer control units 14A-14N provided in the power output circuits 2aA-2aN, 2bA-2bN connected to the secondary windings TR2A-TR2N of the isolation transformer TR, respectively, monitor device operation information such as the output DC voltage Vdc, the output DC current If applied to the load, or the temperature of the regulator circuits 15A-15N, and have the function of transmitting the device operation information to the higher-level control system 10. Therefore, the higher-level control system 10 can monitor the application conditions for the load in real time, and can instruct the AC power source PS to output values ​​that optimize the application conditions of the AC power source PS input to the isolation transformer TR, thereby performing DC conversion. As a result, in the regulator circuits 15A to 15N, DC voltage control with suppressed voltage drop is possible, and further, in the complementary circuit composed of nMos and pMos, the current applied to the load is controlled to stabilize the DC voltage by the sink and source action, which has the effect of suppressing heat generation due to the small voltage drop, and the cooling structure can be made smaller, thereby enabling the power supply device to be made more compact.

[0026] Embodiment 2 (1) Detailed description of the configuration Next, a power supply device 1c according to a second embodiment will be described with reference to FIG. The power supply device 1c according to the second embodiment is different in that, whereas the power supply devices 1a and 1b according to the first embodiment are provided with a single primary winding and a plurality of secondary windings arranged corresponding to each primary winding, the power supply device 1c according to the second embodiment is provided with a plurality of primary windings and a plurality of secondary windings arranged corresponding to each primary winding. Note that the basic configuration of the power supply device is the same as that of the first embodiment, and therefore a description of the same or equivalent parts as those of the first embodiment will be omitted.

[0027] 3, the insulating transformers TRA, TRB, ..., TRN each have a pair of transformers, each of which is made up of a primary winding TR1A, TR1B, ..., TR1N and a secondary winding TR2A, TR2B, ..., TR2N, and each of the secondary windings TR2A to TR2N is connected to a power output circuit 2cA, 2cB, ..., 2cN, respectively. The configuration of each power output circuit is the same as that of the first embodiment.

[0028] One end of each of the primary windings TR1A to TR1N of the isolation transformers TRA to TRN is connected to the output of the AC power supply PS via switches SW11A, SW11B, ..., SW11N, and the other end is connected to the N side of the AC power supply PS. Therefore, the isolation transformer and the DC power supply output circuit form a pair to form a multi-output power supply device. As in the first embodiment, the AC power supply PS can variably output the output frequency and voltage according to an external command, and can apply an AC voltage with a higher frequency than the commercial AC frequency to the primary windings TR1A to TR1N.

[0029] In power supply device 1c, upper control system 10 and microcomputer control unit are the same as in embodiment 1, and the means by which the microcomputer control unit cuts off the abnormal system when an abnormality is transmitted from the operation information of the power supply output is also the same as in embodiment 1. However, power supply device 1c differs from embodiment 1 in that the output of DC voltage to each load is cut off by cutting off the switch of each system connected to the primary side of the isolation transformer.

[0030] (2) Key points and features of the implementation example As described above, the power supply device 1c according to the second embodiment of the present disclosure is a multi-output power supply device, but is provided with individual isolation transformers corresponding to the respective power supply outputs. Also, as in the first embodiment, the power supply device 1c is capable of applying an AC voltage with a higher frequency than the commercial AC power supply to the primary side of the isolation transformer, and by applying an AC voltage with a higher frequency than the commercial AC power supply, the size can be reduced due to the magnetic flux density relationship. Also, each isolation transformer provided for multiple power supply outputs can be a transformer with a small current capacity, and the power supply device can be made smaller by mounting the isolation transformer and the power supply output circuit for generating direct current on a single board.

[0031] In any of the above-described embodiments, the power supply device is not limited to one having a plurality of power output circuits, and may be one having a single power output circuit. In addition, the present disclosure allows for free combinations of the embodiments, modifications of any of the components of the embodiments, or omission of any of the components of the embodiments.

[0032] Various aspects of the present disclosure are summarized below as appendices.

[0033] (Appendix 1) a power supply input circuit including: an isolation transformer having a primary winding and a secondary winding insulated from the primary winding; and an AC power supply having a variable output voltage that excites the primary winding with the output voltage; a power supply output circuit connected to the secondary winding, converting an AC voltage input from the secondary winding by excitation of the primary winding into a DC voltage and outputting the DC voltage to a load; a voltage control unit that controls an output voltage of the AC power supply and a DC voltage output from the power supply output circuit to the load. A power supply device comprising: (Appendix 2) The AC power supply has a variable output voltage and output frequency, The voltage control unit controls an output voltage and an output frequency of the AC power supply and a DC voltage output from the power supply output circuit to the load. 2. The power supply device according to claim 1 . (Appendix 3) a plurality of power output circuits including the power output circuit, the isolation transformer has a plurality of secondary windings including the secondary winding insulated from the primary winding, The plurality of power output circuits are connected to the plurality of secondary windings, respectively, and convert AC voltages input from the plurality of secondary windings by excitation of the primary windings into DC voltages and output the DC voltages to a plurality of loads. 3. The power supply device according to claim 1 or 2. (Appendix 4) a plurality of power output circuits including the power output circuit, the isolation transformer has a plurality of primary windings including the primary winding, and a plurality of secondary windings including the secondary winding arranged corresponding to each of the plurality of primary windings and insulated from the plurality of primary windings, The plurality of power supply output circuits are connected to the plurality of secondary windings, respectively, and convert AC voltages input from the plurality of secondary windings by exciting the plurality of primary windings into DC voltages and output the DC voltages to a plurality of loads. 4. The power supply device according to claim 1, (Appendix 5) The power output circuit includes a notification unit that notifies when a difference between a preset voltage and a DC voltage output to the load exceeds a preset threshold. 5. The power supply device according to claim 1, (Appendix 6) The power output circuit includes a cutoff unit that cuts off the output of the DC voltage to the load when a difference between a preset voltage and the DC voltage output to the load exceeds a preset threshold. 6. The power supply device according to claim 1, [Explanation of symbols]

[0034] 1a power supply, 1b power supply, 1c power supply, 2aA power output circuit, 2aB power output circuit, 2aN power output circuit, 2bA power output circuit, 2bB power output circuit, 2bN power output circuit, 2cA power output circuit, 2cB power output circuit, 2cN power output circuit, 10 upper control system (voltage control section), 11A rectifier diode bridge, 11B rectifier diode bridge, 12A smoothing capacitor, 12B smoothing capacitor, 13A control circuit section, 13B control circuit section, 14A microcomputer control section (alarm section, cutoff section), 14B microcomputer control section (alarm section, cutoff section), 14N microcomputer control section (alarm section, cutoff section), 15A regulator circuit, 15B regulator circuit, 15N regulator circuit, 16n control element, 16p control element, G gate input section, SW11A switch, SW11B switch, SW11N Switch, SW1A switch, SW1B switch, TR isolation transformer (power input circuit), TRA isolation transformer (power input circuit), TRB isolation transformer (power input circuit), TR1 primary winding, TR1A primary winding, TR1B primary winding, TR1N primary winding, TR2A secondary winding, TR2B secondary winding, TR2N secondary winding, PS AC power supply (power input circuit).

Claims

1. a power supply input circuit including: an isolation transformer having a primary winding and a secondary winding insulated from the primary winding; and an AC power supply having a variable output voltage that excites the primary winding with the output voltage; a power supply output circuit connected to the secondary winding, converting an AC voltage input from the secondary winding by excitation of the primary winding into a DC voltage and outputting the DC voltage to a load; a voltage control unit that controls an output voltage of the AC power supply and a DC voltage output from the power supply output circuit to the load. A power supply device comprising:

2. The AC power supply has a variable output voltage and output frequency, The voltage control unit controls the output voltage and output frequency of the AC power supply and the DC voltage output from the power supply output circuit to the load.

2. The power supply device according to claim 1.

3. a plurality of power output circuits including the power output circuit, the isolation transformer has a plurality of secondary windings including the secondary winding insulated from the primary winding, The plurality of power output circuits are connected to the plurality of secondary windings, respectively, and convert AC voltages input from the plurality of secondary windings by excitation of the primary windings into DC voltages and output the DC voltages to a plurality of loads.

2. The power supply device according to claim 1.

4. a plurality of power output circuits including the power output circuit, the isolation transformer has a plurality of primary windings including the primary winding, and a plurality of secondary windings including the secondary winding arranged corresponding to each of the plurality of primary windings and insulated from the plurality of primary windings, The plurality of power supply output circuits are connected to the plurality of secondary windings, respectively, and convert AC voltages input from the plurality of secondary windings by exciting the plurality of primary windings into DC voltages and output the DC voltages to a plurality of loads.

2. The power supply device according to claim 1.

5. The power output circuit includes a notification unit that notifies when a difference between a preset voltage and a DC voltage output to the load exceeds a preset threshold.

5. The power supply device according to claim 1, wherein the first and second electrodes are electrically connected to each other.

6. The power output circuit includes a cutoff unit that cuts off the output of the DC voltage to the load when a difference between a preset voltage and the DC voltage output to the load exceeds a preset threshold.

5. The power supply device according to claim 1, wherein the first and second electrodes are electrically connected to each other.

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