Power supply device and method for controlling the power supply device

Abstract

To provide a power supply device and a control method for a power supply device that can reduce an inrush current.SOLUTION: The power supply device includes: a plurality of converters; a rectification circuit including a plurality of rectification arms that rectifies output voltages of the plurality of converters for output to a load; and a control circuit that controls the plurality of converters. One of output terminals of each of the plurality of converters is electrically connected to the other output terminal of an adjacent one of the converters, and is electrically connected to a rectification arm of the plurality of rectification arms. The control circuit exerts control of causing the plurality of converters to start operation one by one at power-on.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power supply device and a method for controlling a power supply device. [Background technology]

[0002] Patent Document 1 describes a power conversion device having a first operating mode in which all switching elements of the first to third switching legs are operated in a switching manner, and a second operating mode in which at least one of the first to third switching legs, either the upper or lower switching element, is always on, and the other switching element is always off. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-173961 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a power supply device in which a plurality of current resonant converters are connected in series, a large inrush current flows when the power supply is turned on.

[0005] An object of the present invention is to provide a power supply device and a method for controlling the power supply device that are capable of suppressing inrush current. [Means for solving the problem]

[0006] A power supply device according to one aspect of the present invention comprises: A plurality of converters; a rectifier circuit including a plurality of rectifier arms that rectify the winding voltages of the plurality of converters and output the rectified voltages to a load; A control circuit for controlling the plurality of converters; Equipped with One output terminal of each of the plurality of converters is electrically connected to the other output terminal of each adjacent converter and is electrically connected to one rectifier arm of the plurality of rectifier arms; The control circuit includes: When the power is turned on, the plurality of converters are controlled to start operating one by one. It is characterized by:

[0007] In the power supply device, The control circuit includes: When a predetermined threshold time has elapsed since one of the plurality of converters was started to operate, control is performed to start the operation of the next converter. It is characterized by:

[0008] In the power supply device, The control circuit includes: One of the plurality of converters is started to operate, and when the output current of the converter becomes equal to or lower than a predetermined threshold current, the next converter is started to operate. It is characterized by:

[0009] In the power supply device, Each of the plurality of converters is a current resonant converter. It is characterized by:

[0010] A method for controlling a power supply device according to one aspect of the present invention includes: A control method for a power supply device comprising: a rectifier circuit including a plurality of converters; a plurality of rectifier arms that rectify winding voltages of the plurality of converters and output the rectified voltages to a load; and a control circuit that controls the plurality of converters, wherein one output terminal of each of the plurality of converters is electrically connected to the other output terminal of an adjacent converter and is also electrically connected to one rectifier arm of the plurality of rectifier arms, the control method comprising the steps of: When power is turned on, the plurality of converters are started to operate one by one. It is characterized by: Effect of the Invention

[0011] Advantageous Effects of Invention The power supply device and the method for controlling the power supply device according to one aspect of the present invention provide an advantage in that inrush current can be suppressed. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating a circuit configuration of a power supply device according to a first embodiment. [Diagram 2] FIG. 2 is a diagram showing a circuit configuration of a full-bridge circuit of the power supply device according to the first embodiment. [Diagram 3] FIG. 3 is a diagram illustrating modes of the power supply device according to the first embodiment. [Figure 4] FIG. 4 is a diagram showing the direction of voltage (current) on the secondary winding side of the power supply device according to the first embodiment. [Diagram 5] FIG. 5 is a diagram showing the output voltage and the output current of the power supply device of the comparative example. [Figure 6] FIG. 6 is a flowchart showing the operation of the control circuit of the power supply device according to the first embodiment when the power supply is turned on. [Figure 7] FIG. 7 is a diagram illustrating an output voltage and an output current of the power supply device according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A power supply device and a method for controlling the power supply device according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the present invention is not limited to the embodiment.

[0014] <First embodiment and comparative example> (Overall composition) 1 is a diagram showing a circuit configuration of a power supply device according to a first embodiment. The power supply device 1 receives a DC voltage Vin that is output from a DC power supply 21 and smoothed by a capacitor 22, and outputs an output voltage Vout to a load 23.

[0015] The power supply device 1 includes a first current resonant converter 2-1 to a fourth current resonant converter 2-4, a rectifier circuit 3, a control circuit 4, a capacitor 5, a voltage sensor 6, and a current sensor .

[0016] In the first embodiment, the number of current resonant converters is an even number (four as a representative even number), but the present disclosure is not limited to this. The number of current resonant converters may be an odd number. In the first embodiment, the number of current resonant converters is four, but the number of current resonant converters may be two, or six or more.

[0017] Furthermore, each converter is not limited to a current resonant converter.

[0018] Each of the first current resonant converter 2-1 to the fourth current resonant converter 2-4 is a current resonant converter (LLC converter) that utilizes LLC resonance. Each of the first current resonant converter 2-1 to the fourth current resonant converter 2-4 is electrically connected to a capacitor 22. A DC voltage Vin that is output from a DC power supply 21 and smoothed by the capacitor 22 is input to each of the first current resonant converter 2-1 to the fourth current resonant converter 2-4.

[0019] The first current resonant converter 2-1 includes a first full-bridge circuit FB1 and a first transformer T1. The first current resonant converter 2-1 includes a leakage inductance 14-1 and a capacitor 15-1 between the first full-bridge circuit FB1 and the first transformer T1. The leakage inductance 14-1 may be included in the first transformer T1.

[0020] The second current resonant converter 2-2 includes a second full-bridge circuit FB2 and a second transformer T2. The second current resonant converter 2-2 includes a leakage inductance 14-2 and a capacitor 15-2 between the second full-bridge circuit FB2 and the second transformer T2. The leakage inductance 14-2 may be included in the second transformer T2.

[0021] The third current resonant converter 2-3 includes a third full-bridge circuit FB3 and a third transformer T3. The third current resonant converter 2-3 includes a leakage inductance 14-3 and a capacitor 15-3 between the third full-bridge circuit FB3 and the third transformer T3. The leakage inductance 14-3 may be included in the third transformer T3.

[0022] The fourth current resonant converter 2-4 includes a fourth full-bridge circuit FB4 and a fourth transformer T4. The fourth current resonant converter 2-4 includes a leakage inductance 14-4 and a capacitor 15-4 between the fourth full-bridge circuit FB4 and the fourth transformer T4. The leakage inductance 14-4 may be included in the fourth transformer T4.

[0023] Fig. 2 is a diagram showing a circuit configuration of a full-bridge circuit of the power supply device according to the first embodiment. Although Fig. 2 shows the circuit configuration of the first full-bridge circuit FB1, the circuit configurations of the second full-bridge circuit FB2 to the fourth full-bridge circuit FB4 are similar to the circuit configuration of the first full-bridge circuit FB1, and therefore illustration and description thereof are omitted.

[0024] The first full-bridge circuit FB1 includes a first arm 30-1 and a second arm 30-2. The first arm 30-1 includes a high-side transistor Tr1-1 and a low-side transistor Tr1-2. The second arm 30-2 includes a high-side transistor Tr2-1 and a low-side transistor Tr2-2.

[0025] In the present disclosure, each transistor is a MOSFET, but is not limited to this. Each transistor may be a silicon power device, a GaN power device, a SiC power device, an IGBT (Insulated Gate Bipolar Transistor), or the like.

[0026] Each transistor has a parasitic diode (body diode). A parasitic diode is a pn junction between the back gate and the source and drain of a MOSFET. The parasitic diode can be used as a freewheeling diode to release the transient back electromotive force when the transistor is turned off.

[0027] The source of the transistor Tr1-1 is electrically connected to the drain of the transistor Tr1-2, and the source of the transistor Tr2-1 is electrically connected to the drain of the transistor Tr2-2.

[0028] The drain of the transistor Tr1-1 and the drain of the transistor Tr2-1 are electrically connected to one end (high potential end) of the capacitor 22. The source of the transistor Tr1-2 and the source of the transistor Tr2-2 are electrically connected to the other end (low potential end) of the capacitor 22.

[0029] A connection point between the drain of the transistor Tr1-1 and the drain of the transistor Tr2-1 is one input terminal of the first full-bridge circuit FB1, and a connection point between the source of the transistor Tr1-2 and the source of the transistor Tr2-2 is the other input terminal of the first full-bridge circuit FB1.

[0030] A DC voltage Vin is input to two input terminals of the first full-bridge circuit FB1.

[0031] The connection point between the source of the transistor Tr1-1 and the drain of the transistor Tr1-2 is one output terminal of the first full-bridge circuit FB1, and the connection point between the source of the transistor Tr1-2 and the drain of the transistor Tr2-2 is the other output terminal of the first full-bridge circuit FB1.

[0032] The first full-bridge circuit FB1 outputs a DC voltage Vin, a DC voltage −Vin, or a zero voltage between one output terminal and the other output terminal.

[0033] For example, when the transistors Tr1-1 and Tr2-2 are on and the transistors Tr1-2 and Tr2-1 are off, the first full-bridge circuit FB1 outputs a DC voltage Vin between one output terminal and the other output terminal.

[0034] Also, for example, when the transistors Tr1-1 and Tr2-2 are in an off state and the transistors Tr1-2 and Tr2-1 are in an on state, the first full-bridge circuit FB1 outputs a DC voltage -Vin between one output terminal and the other output terminal.

[0035] Furthermore, for example, when the transistors Tr1-1 to Tr2-2 are in the off state, the first full-bridge circuit FB1 outputs zero voltage between one output terminal and the other output terminal.

[0036] 1, the first transformer T1 includes a primary winding 10-1, a secondary winding 11-1, and a core 12-1. The primary winding 10-1 and the secondary winding 11-1 are wound around the core 12-1.

[0037] The primary winding 10-1 includes an excitation inductance 13-1 and a leakage inductance 14-1. One end of the primary winding 10-1 is electrically connected to one output terminal of the first full-bridge circuit FB1 via a capacitor 15-1. The other end of the primary winding 10-1 is electrically connected to the other output terminal of the first full-bridge circuit FB1. The excitation inductance 13-1, the leakage inductance 14-1, and the capacitor 15-1 form an LLC resonant circuit.

[0038] In the present disclosure, the LLC resonant circuit is located on the side of the primary winding 10-1, but this is not limiting. The LLC resonant circuit may be located on the side of the secondary winding 11-1. The LLC resonant circuit may be located on both the side of the primary winding 10-1 and the side of the secondary winding 11-1.

[0039] The second transformer T2 includes a primary winding 10-2, a secondary winding 11-2, and a core 12-2. The primary winding 10-2 includes an excitation inductance 13-2 and a leakage inductance 14-2. The connections of these elements of the second transformer T2 are similar to those of the first transformer T1, and therefore will not be described.

[0040] The third transformer T3 includes a primary winding 10-3, a secondary winding 11-3, and a core 12-3. The primary winding 10-3 includes an excitation inductance 13-3 and a leakage inductance 14-3. The connections of these elements of the third transformer T3 are similar to those of the first transformer T1, and therefore will not be described.

[0041] The fourth transformer T4 includes a primary winding 10-4, a secondary winding 11-4, and a core 12-4. The primary winding 10-4 includes an excitation inductance 13-4 and a leakage inductance 14-4. The connections of these elements of the fourth transformer T4 are similar to those of the first transformer T1, and therefore will not be described.

[0042] The rectifier circuit 3 is a bridge diode and includes a first rectifier arm 3-1 to a fifth rectifier arm 3-5.

[0043] The first rectifier arm 3-1 includes a high-side diode D1-1 and a low-side diode D1-2, the anode of which is electrically connected to the cathode of the diode D1-2.

[0044] The connection point between the anode of the diode D1-1 and the cathode of the diode D1-2 is the input terminal of the first rectifier arm 3-1. The cathode of the diode D1-1 is one output terminal (high potential side) of the first rectifier arm 3-1. The anode of the diode D1-2 is the other output terminal (low potential side) of the first rectifier arm 3-1.

[0045] The second rectifier arm 3-2 includes a high-side diode D2-1 and a low-side diode D2-2, the anode of which is electrically connected to the cathode of the diode D2-2.

[0046] The connection point between the anode of the diode D2-1 and the cathode of the diode D2-2 is the input terminal of the second rectifier arm 3-2. The cathode of the diode D2-1 is one (high potential side) output terminal of the second rectifier arm 3-2. The anode of the diode D2-2 is the other (low potential side) output terminal of the second rectifier arm 3-2.

[0047] The third rectifier arm 3-3 includes a high-side diode D3-1 and a low-side diode D3-2, the anode of which is electrically connected to the cathode of the diode D3-2.

[0048] The connection point between the anode of the diode D3-1 and the cathode of the diode D3-2 is the input terminal of the third rectifier arm 3-3. The cathode of the diode D3-1 is one output terminal (high potential side) of the third rectifier arm 3-3. The anode of the diode D3-2 is the other output terminal (low potential side) of the third rectifier arm 3-3.

[0049] The fourth rectifier arm 3-4 includes a high-side diode D4-1 and a low-side diode D4-2, the anode of which is electrically connected to the cathode of the diode D4-2.

[0050] The connection point between the anode of the diode D4-1 and the cathode of the diode D4-2 is the input terminal of the fourth rectifier arm 3-4. The cathode of the diode D4-1 is one output terminal (high potential side) of the fourth rectifier arm 3-4. The anode of the diode D4-2 is the other output terminal (low potential side) of the fourth rectifier arm 3-4.

[0051] The fifth rectifier arm 3-5 includes a high-side diode D5-1 and a low-side diode D5-2, the anode of which is electrically connected to the cathode of the diode D5-2.

[0052] The connection point between the anode of the diode D5-1 and the cathode of the diode D5-2 is the input terminal of the fifth rectifier arm 3-5. The cathode of the diode D5-1 is one output terminal of the fifth rectifier arm 3-5. The anode of the diode D5-2 is the other output terminal of the fifth rectifier arm 3-5.

[0053] The input terminal of the first rectifier arm 3-1 is electrically connected to one end 11-1a of the secondary winding 11-1 of the first transformer T1. The input terminal of the second rectifier arm 3-2 is electrically connected to the other end 11-1b of the secondary winding 11-1 of the first transformer T1 and one end 11-2a of the secondary winding 11-2 of the second transformer T2. The input terminal of the third rectifier arm 3-3 is electrically connected to the other end 11-2b of the secondary winding 11-2 of the second transformer T2 and one end 11-3a of the secondary winding 11-3 of the third transformer T3.

[0054] An input terminal of the fourth rectifier arm 3-4 is electrically connected to the other end 11-3b of the secondary winding 11-3 of the third transformer T3 and one end 11-4a of the secondary winding 11-4 of the fourth transformer T4. An input terminal of the fifth rectifier arm 3-5 is electrically connected to the other end 11-4b of the secondary winding 11-4 of the fourth transformer T4.

[0055] That is, one output terminal of each of the first current resonant converter 2-1 to the fourth current resonant converter 2-4 is electrically connected to the other output terminal of the adjacent (one above in FIG. 1) current resonant converter, and is also electrically connected to one of the rectifier arms of the first rectifier arm 3-1 to the fifth rectifier arm 3-5. For example, one output terminal (one end 11-4a of the secondary winding 11-4) of the fourth current resonant converter 2-4 is electrically connected to the other output terminal (the other end 11-3b of the secondary winding 11-3) of the adjacent (one above in FIG. 1) third current resonant converter 2-3, and is also electrically connected to the fourth rectifier arm 3-4. Note that one output terminal (one end 11-1a of the secondary winding 11-1) of the first current resonant converter 2-1 is electrically connected alone to the first rectifier arm 3-1.

[0056] In the present disclosure, adjacent current resonant converters are not limited to being adjacent geographically, but may be adjacent electrically (in terms of wiring). For example, in FIG. 1, the first current resonant converter 2-1 and the second current resonant converter 2-2 are not limited to being adjacent geographically. However, from the viewpoint of simplifying wiring, reducing wiring length, etc., it is preferable that adjacent current resonant converters are adjacent geographically and adjacent electrically (in terms of wiring).

[0057] The cathodes of the diodes D1-1 to D5-1 are electrically connected and form one (high potential side) output terminal of the rectifier circuit 3. The anodes of the diodes D1-2 to D5-2 are electrically connected and form the other (low potential side) output terminal of the rectifier circuit 3. The cathodes of the diodes D1-1 to D5-1 are electrically connected to one end (high potential side end) of the capacitor 5. The anodes of the diodes D1-2 to D5-2 are electrically connected to the other end (low potential side end) of the capacitor 5.

[0058] Rectifier circuit 3 full-wave rectifies the voltage excited across secondary windings 11-1 to 11-4 and outputs the full-wave rectified voltage to capacitor 5. Capacitor 5 smoothes the voltage that has been full-wave rectified by rectifier circuit 3. The voltage of capacitor 5 is the output voltage Vout.

[0059] One end (high potential end) of the capacitor 5 is electrically connected to one end (for example, the positive electrode of a lithium ion battery) of the load 23. The other end (low potential end) of the capacitor 5 is electrically connected to the other end (for example, the negative electrode of a lithium ion battery) of the load 23.

[0060] The output voltage Vout smoothed by the capacitor 5 is input to the load 23. For example, if the load 23 is a lithium ion battery, the lithium ion battery is charged by the output voltage Vout smoothed by the capacitor 5.

[0061] The voltage sensor 6 detects the output voltage Vout and outputs a voltage detection signal S1 to the control circuit 4. The current sensor 7 detects the output current Iout flowing through the load 23 and outputs a current detection signal S2 to the control circuit 4.

[0062] The output setting unit 24 outputs to the control circuit 4 a voltage setting value signal S3 for the output voltage Vout and a current setting value signal S4 for the output current Iout.

[0063] For example, when the load 23 is a lithium-ion battery, the output setting unit 24 outputs to the control circuit 4 a voltage set value signal S3 and a current set value signal S4 that change the output voltage Vout from 50V to 1000V while maintaining the output current Iout constant at 5A. That is, the output setting unit 24 changes the signal value of the voltage set value signal S3 from "50V" to "1000V" while maintaining the signal value of the current set value signal S4 at "5A". Then, when the output voltage Vout reaches 1000V, the output setting unit 24 outputs to the control circuit 4 a voltage set value signal S3 and a current set value signal S4 that change the output current Iout from 5A to 0A while maintaining the output voltage Vout constant at 1000V. That is, the output setting unit 24 changes the signal value of the current set value signal S4 from "5A" to "0A" while maintaining the signal value of the voltage set value signal S3 at "1000V".

[0064] The voltage set value signal S3 and the current set value signal S4 are illustrated as signals conforming to CHAdeMO (trademark), but the present disclosure is not limited thereto.

[0065] The control circuit 4 switches the mode (the number of operating converters) based on a voltage detection signal S1 input from the voltage sensor 6, a current detection signal S2 input from the current sensor 7, and a voltage set value signal S3 and a current set value signal S4 input from the output setting unit 24. Then, the control circuit 4 outputs switching control signals to the first full-bridge circuit FB1 to the fourth full-bridge circuit FB4 so that the output voltage Vout and the output current Iout each become the set value.

[0066] 3 is a diagram showing the modes of the power supply device according to the first embodiment. The power supply device 1 has four modes, from a first mode to a fourth mode.

[0067] As shown in the first column 51 of table 50, in the first mode, all of the first current resonant converter 2-1 to the fourth current resonant converter 2-4 are turned on (operated). The first mode is the mode with the largest output.

[0068] As shown in the second column 52 of table 50, in the second mode, the first current resonant converter 2-1 to the third current resonant converter 2-3 are turned on, and the fourth current resonant converter 2-4 is turned off (stopped). The second mode is the mode with the second largest output.

[0069] As shown in the third column 53 of table 50, in the third mode, the first current resonant converter 2-1 and the second current resonant converter 2-2 are turned on, and the third current resonant converter 2-3 and the fourth current resonant converter 2-4 are turned off. The third mode is the mode with the third largest output.

[0070] As shown in the fourth column 54 of table 50, in the fourth mode, the first current resonant converter 2-1 is turned on and the second current resonant converter 2-2 to the fourth current resonant converter 2-4 are turned off. The fourth mode is the mode with the smallest output.

[0071] Fig. 4 is a diagram showing the direction of voltage (current) on the secondary winding side of the power supply device of the first embodiment. In detail, Fig. 4 is a diagram showing the direction of voltage (current) on the secondary winding side of the first transformer T1 and the second transformer T2 when a positive voltage 61 is applied to the primary winding 10-1 of the first transformer T1 and a positive voltage 62 is applied to the primary winding 10-2 of the second transformer T2.

[0072] In this case, a voltage is generated in the primary winding 10-1 of the first transformer T1 in the direction indicated by an arrow 63, and a voltage is generated in the primary winding 10-2 of the second transformer T2 in the direction indicated by an arrow 64. Therefore, on the secondary winding side of the first transformer T1 and the second transformer T2, as indicated by an arrow 65, a voltage is generated on a path from the diode D1-2 → one end 11-1a of the secondary winding 11-1 of the first transformer T1 → the other end 11-1b of the secondary winding 11-1 of the first transformer T1 → one end 11-2a of the secondary winding 11-2 of the second transformer T2 → the other end 11-2b of the secondary winding 11-2 of the second transformer T2 → the diode D3-1.

[0073] In other words, when one current resonant converter and an adjacent current resonant converter have the same output polarity, the secondary windings are connected in series (voltage addition).

[0074] The control circuit 4 controls the output polarity of one current resonant converter to be the same as that of an adjacent current resonant converter, thereby making it possible to increase the voltage while maintaining the current.

[0075] (Comparative Example) In the comparative example, the control circuit 4 simultaneously starts the operation of all of the first current resonant converter 2-1 to the fourth current resonant converter 2-4 when the power is turned on.

[0076] 5 is a diagram showing the output voltage and output current of a power supply device of a comparative example. Waveform 71 is the waveform of the output current Iout. Waveform 72 is the waveform of the output voltage Vout.

[0077] At timing t0, when all of the first current resonant converter 2-1 to the fourth current resonant converter 2-4 start operating simultaneously, the output current Iout becomes a large inrush current I0, as shown by waveform 71. The output current Iout decreases over time and eventually converges to a current I1. Also, as shown by waveform 72, the output voltage Vout increases over time and eventually converges to a voltage V0.

[0078] When such a large inrush current I0 flows, the burden of the peak current is large on the DC power supply 21, the capacitor 22, the diodes D1-1 to D5-2, the capacitor 5, the load 23, etc. In addition, since the capacitor 22, the diodes D1-1 to D5-2, and the capacitor 5 must be large components, the device becomes larger and more expensive.

[0079] (First embodiment) FIG. 6 is a flowchart showing the operation of the control circuit of the power supply device according to the first embodiment when the power supply is turned on.

[0080] 6, in step S10, the control circuit 4 starts the operation of the first current resonant converter 2-1. That is, the control circuit 4 operates the power supply device 1 in the fourth mode.

[0081] In step S12, the control circuit 4 determines whether or not a predetermined threshold time has elapsed. If the control circuit 4 determines that the threshold time has not elapsed (No in step S12), it waits in step S12. If the control circuit 4 determines that the threshold time has elapsed (Yes in step S12), it advances the process to step S14.

[0082] In step S14, the control circuit 4 starts the operation of the second current resonant converter 2-2. That is, the control circuit 4 operates the power supply device 1 in the third mode.

[0083] In step S16, control circuit 4 determines whether the threshold time has elapsed. If control circuit 4 determines that the threshold time has not elapsed (No in step S16), it waits in step S16. If control circuit 4 determines that the threshold time has elapsed (Yes in step S16), it advances the process to step S18.

[0084] In step S18, control circuit 4 starts the operation of the third current resonance converter 2-3. That is, control circuit 4 operates the power supply device 1 in the second mode.

[0085] In step S20, control circuit 4 determines whether the threshold time has elapsed. If control circuit 4 determines that the threshold time has not elapsed (No in step S20), it waits in step S20. If control circuit 4 determines that the threshold time has elapsed (Yes in step S20), it advances the process to step S22.

[0086] In step S22, control circuit 4 starts the operation of the fourth current resonance converter 2-4. That is, control circuit 4 operates the power supply device 1 in the first mode. Then, control circuit 4 ends the processing at power-on.

[0087] Thus, the control circuit 4 of the power supply device 1 according to the first embodiment starts the operation of the plurality of current resonance converters one by one.

[0088] FIG. 7 is a diagram showing the output voltage and output current of the power supply device according to the first embodiment. Waveform 73 is the waveform of the output current Iout. Waveform 74 is the waveform of the output voltage Vout.

[0089] Timing t 10 When the first current resonance converter 2-1 starts operating, as shown by waveform 73, the output current Iout becomes a small inrush current I 10 Here, I 10 < I0. The output current Iout decreases as time elapses and eventually becomes current I 11Moreover, as shown by the waveform 74, the output voltage Vout increases as time passes.

[0090] Timing 10 After the threshold time has elapsed from 11 When the second current resonant converter 2-2 starts operating, the output current Iout becomes a small inrush current as shown by the waveform 73. The output current Iout decreases over time and eventually converges. Also, as shown by the waveform 74, the output voltage Vout increases over time.

[0091] Timing 11 After the threshold time has elapsed from 12 When the third current resonant converter 2-3 starts operating, the output current Iout becomes a small inrush current as shown by the waveform 73. The output current Iout decreases over time and eventually converges. Also, as shown by the waveform 74, the output voltage Vout increases over time.

[0092] Timing 12 After the threshold time has elapsed from 13 In this case, when the fourth current resonant converter 2-4 starts operating, the output current Iout becomes a small inrush current as shown by the waveform 73. The output current Iout decreases over time and eventually converges. Also, as shown by the waveform 74, the output voltage Vout increases over time.

[0093] As described above, the power supply device 1 of the first embodiment has a smaller inrush current I 10 can be made smaller than the inrush current I0. This allows the power supply device 1 to reduce the burden of peak currents on the DC power supply 21, the capacitor 22, the diodes D1-1 to D5-2, the capacitor 5, the load 23, etc. Furthermore, the power supply device 1 does not need to make the capacitor 22, the diodes D1-1 to D5-2, and the capacitor 5 large components, allowing the device to be made smaller and less expensive.

[0094] <Second embodiment> The circuit configuration of the power supply device of the second embodiment is similar to the circuit configuration of the power supply device 1 of the first embodiment, and therefore will not be illustrated or described.

[0095] In the first embodiment, the control circuit 4 starts the operation of the next current resonant converter when a threshold time has elapsed since the start of operation of one current resonant converter.

[0096] On the other hand, in the second embodiment, the control circuit 4 starts the operation of one current resonant converter, and at the timing when the output current Iout becomes equal to or lower than a predetermined threshold current, starts the operation of the next current resonant converter.

[0097] In this case, the control circuit 4 may determine whether or not the output current Iout has become equal to or lower than the threshold current in each of steps S12, S16, and S20 of the flowchart in FIG. 6 described in the first embodiment.

[0098] The power supply device of the second embodiment has the same effects as the first embodiment.

[0099] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0100] 1 Power supply 2-1 First current resonant converter 2-2 Second current resonant converter 2-3 Third current resonant converter 2-4 Fourth current resonant converter 3 Rectifier circuit 4 Control circuit 5, 22 Capacitor 6 Voltage Sensor 7 Current Sensor 21 DC power supply 23 Load 24 Output setting section FB1 First full bridge circuit FB2 Second full bridge circuit FB3 3rd full bridge circuit FB4 4th full bridge circuit T1 1st transformer T2 Second transformer T3 3rd transformer T4 4th transformer

Claims

1. A plurality of converters; a rectifier circuit including a plurality of rectifier arms that rectify output voltages of the plurality of converters and output the rectified output voltages to a single load; A control circuit for controlling the plurality of converters; Equipped with one output terminal of each of the plurality of converters is electrically connected to the other output terminal of each adjacent converter and is electrically connected to one rectifier arm of the plurality of rectifier arms; The control circuit includes: At a first timing, a first converter among the plurality of converters is started to operate, and an output voltage of the first converter is output to the one load; At a second timing when the output current of the first converter becomes equal to or lower than a predetermined threshold current after the first timing, a second converter electrically adjacent to the first converter is started to operate with the same output polarity as the first converter, thereby connecting the output of the first converter and the output of the second converter in series, and outputting a voltage which is the sum of the output voltage of the first converter and the output voltage of the second converter to the one load. A power supply device comprising:

2. The control circuit includes: at a third timing when the output currents of the first converter and the second converter become equal to or lower than the threshold current after the second timing, a third converter electrically adjacent to the second converter is started to operate with the same output polarity as the first converter and the second converter, thereby connecting the outputs of the first converter to the third converter in series and outputting a voltage that is the sum of the output voltages of the first converter to the third converter to the single load; At a fourth timing when the output current from the first converter to the third converter becomes equal to or less than the threshold current after the third timing, a fourth converter electrically adjacent to the third converter is started to operate with the same output polarity as the first converter to the third converter, thereby connecting the outputs from the first converter to the fourth converter in series and outputting a voltage that is the sum of the output voltages from the first converter to the fourth converter to the single load; The inrush current of the output current output to the one load is suppressed compared to a case where all of the first converter to the fourth converter are started to operate simultaneously.

2. The power supply device according to claim 1 .

3. Each of the plurality of converters is a current resonant converter.

3. The power supply device according to claim 1 or 2.

4. A control method for a power supply device comprising: a rectifier circuit including a plurality of converters; a plurality of rectifier arms that rectify output voltages of the plurality of converters and output the rectified output voltages to a single load; and a control circuit that controls the plurality of converters, wherein one output terminal of each of the plurality of converters is electrically connected to the other output terminal of an adjacent converter and is also electrically connected to one rectifier arm of the plurality of rectifier arms, At a first timing, a first converter among the plurality of converters is started to operate, and an output voltage of the first converter is output to the one load; At a second timing when the output current of the first converter becomes equal to or lower than a predetermined threshold current after the first timing, a second converter electrically adjacent to the first converter is started to operate with the same output polarity as the first converter, thereby connecting the output of the first converter and the output of the second converter in series, and outputting a voltage which is the sum of the output voltage of the first converter and the output voltage of the second converter to the one load.

23. A method for controlling a power supply device comprising:

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