Control power supply device

Abstract

The present application provides a control power supply device. The control power supply device (100) has: a pair of input terminals (1, 2); a plurality of input capacitors (Ci1-Cin) connected in series with each other between the pair of input terminals; a plurality of DC-DC conversion circuits (COV1-COVn), each input terminal of which is connected between both ends of each of the plurality of input capacitors; a pair of output terminals (3, 4) connected to the output terminals of the plurality of DC-DC conversion circuits in a manner of connecting the plurality of DC-DC conversion circuits in parallel with each other; a control circuit (5) that receives power supply power from a prescribed input capacitor among the plurality of input capacitors, and outputs a duty cycle control signal (Sc) having a duty cycle corresponding to a target direct current voltage; and a signal converter (6) that converts the duty cycle control signal into an insulated duty cycle control signal (Sc), and inputs the insulated duty cycle control signal to the plurality of DC-DC conversion circuits.

Description

Technical Field

[0001] This invention relates to a power supply control device. Background Technology

[0002] Power conversion systems that form the main circuit of a power converter include, for example, DC power supply devices using DC-DC converters and power storage converters (PCS). In order to control such a power converter, a control power supply device is needed to provide operating power to the control circuit of the power converter. Conventionally, the control power supply device uses the power from the main circuit formed by the power converter as its power source (see Patent Documents 1 and 2).

[0003] Patent Document 1: Japanese Patent No. 6648238 (see reference) Figure 1 and Figure 2 )

[0004] Patent Document 2: Japanese Patent Application Publication No. 2015-027196 (see reference) Figure 4 )

[0005] However, control power supplies typically operate at voltages of a few volts to tens of volts, while the main circuit, including the power converter, operates at voltages exceeding several hundred volts. Therefore, control power supplies also require power converters to step down the voltage of the main circuit. Flyback converters are generally used as such power converters. However, in recent years, the main circuit, composed of these power converters, has become increasingly high-voltage, leading to the need for more high-voltage components in control power supplies. Summary of the Invention

[0006] This invention was made to solve the aforementioned problems. Its first objective is to realize a control power supply device without using high-voltage-resistant components. Furthermore, a second objective of this invention is to prevent the increase in the number of components required to ensure voltage resistance.

[0007] One aspect of this disclosure of a control power supply device comprises: a pair of input terminals to which a DC input voltage is applied; a plurality of input capacitors connected in series between the pair of input terminals for equally distributing the DC input voltage to each input capacitor; a plurality of DC-DC conversion circuits, each of which has its input terminal connected between the two ends of the plurality of input capacitors, each of the plurality of DC-DC conversion circuits being controlled by a duty cycle control signal; a pair of output terminals connected to the output terminals of the plurality of DC-DC conversion circuits in a manner that connects the plurality of DC-DC conversion circuits in parallel with each other; a control circuit that receives power from a predetermined input capacitor, which is one of the plurality of input capacitors, and outputs the duty cycle control signal having a duty cycle corresponding to a target DC voltage; and a signal converter that converts the duty cycle control signal output from the control circuit into a duty cycle control signal insulated from the duty cycle control signal, and inputs the insulated duty cycle control signal to the plurality of DC-DC conversion circuits.

[0008] The present invention can achieve the following effect: it can realize the control power supply device without using high voltage-resistant components. Attached Figure Description

[0009] Figure 1 This is a circuit diagram showing an outline of the structure of the control power supply device according to Embodiment 1 of this disclosure.

[0010] Figure 2 It is shown Figure 1 A circuit diagram illustrating an example of the specific structure of a control power supply device.

[0011] Figure 3 It is shown Figure 2 A circuit diagram illustrating an example of the structure of a control circuit.

[0012] Figure 4 This is a waveform diagram illustrating the operation of an embodiment of the control power supply device of Embodiment 1.

[0013] Label Explanation

[0014] 1: High-potential input terminal (input terminal); 2: Low-potential input terminal (input terminal); 3: High-potential output terminal (output terminal); 4: Low-potential output terminal (output terminal); 5: Control circuit; 6: Signal converter; 7: Operating control power supply; 8: Secondary rectifier circuit; 11: High-potential output terminal; 12: Low-potential output terminal; 20: Output voltage feedback circuit; 31: Control IC; Ci1~Cin: Input capacitor; Co: Output capacitor; Ip: Primary side current; Q1~Qn : Switching element; RCT1~RCTn: Main rectifier circuit; Ris: Primary side current sensing resistor element; Rs: Starting resistor element; Sc: Insulated duty cycle control signal; Sc: Duty cycle control signal; TF1~TFn: Transformer; Vd1~Vdn: Voltage divider; Vin: DC input voltage; Vout: DC output voltage; Vt: Target DC voltage; Wp1~Wpn: Primary winding; Wsm1~Wsmn: Primary and secondary windings; Wss1~Wssn: Secondary winding. Detailed Implementation

[0015] (Insights that led to this invention)

[0016] To achieve the above objectives, the inventors conducted in-depth research. As a result, the following insights were obtained.

[0017] In power supply control devices, as long as the input voltage to DC-DC conversion circuits such as flyback converters can be reduced, the same voltage-rated components as before can be used. To reduce the input voltage to DC-DC conversion circuits, the following three countermeasures were considered.

[0018] i) Use a commercial transformer to step down the input voltage to the control power supply unit.

[0019] ii) The input voltage to the control power supply device is divided by multiple input capacitors connected in series, and the power corresponding to a specific input capacitor among the multiple input capacitors is used as the control power supply.

[0020] iii) The input voltage to the control power supply device is divided by multiple input capacitors connected in series, and the power corresponding to each input capacitor is used as the control power supply.

[0021] However, countermeasure i) has the problem that it cannot be applied to DC lines.

[0022] In countermeasure ii), only one of the aforementioned specific input capacitors is connected to a load (the control circuit of the power converter in the main circuit), so there is a problem that needs to be addressed to balance the voltages divided to each input capacitor.

[0023] In countermeasure iii), multiple DC-DC conversion circuits are set up so that each circuit corresponds to a different input capacitor, which increases the number of components.

[0024] Therefore, the inventors prioritized the ability to apply this to the voltage division between the DC line and the multiple input capacitors, and selected countermeasure iii).

[0025] Furthermore, regarding the problem of countermeasure iii), the inventors, focusing on the point that multiple DC-DC conversion circuits can be controlled with the same duty cycle, conceived of a circuit structure that uses a single duty cycle control signal generated by a single control circuit to control multiple DC-DC conversion circuits. If multiple DC-DC conversion circuits are simply controlled using control circuits corresponding to each of the multiple DC-DC conversion circuits, the number of components in the control power supply device would be the number obtained by multiplying the number of components in a conventional control power supply device by the number of input capacitors. However, according to the above circuit structure, the number of components does not need to be the number obtained by multiplying the number of components in a conventional control power supply device by the number of input capacitors, thus suppressing the increase in the number of components. This disclosure was made based on this insight.

[0026] Therefore, one aspect of the control power supply device of this disclosure includes: a pair of input terminals to which a DC input voltage is applied; a plurality of input capacitors connected in series between the pair of input terminals for equally distributing the DC input voltage to each input capacitor; a plurality of DC-DC conversion circuits, each of which has its input terminal connected between the two ends of the plurality of input capacitors, and each of the plurality of DC-DC conversion circuits is controlled by a duty cycle control signal; a pair of output terminals connected to the output terminals of the plurality of DC-DC conversion circuits in a manner that connects the plurality of DC-DC conversion circuits in parallel with each other; a control circuit that receives power from a predetermined input capacitor, which is one of the plurality of input capacitors, and outputs the duty cycle control signal having a duty cycle corresponding to a target DC voltage; and a signal converter that converts the duty cycle control signal output from the control circuit into a duty cycle control signal that is isolated from the duty cycle control signal, and inputs the isolated duty cycle control signal to the plurality of DC-DC conversion circuits.

[0027] According to this structure, in the control power supply device, a DC-DC conversion circuit is provided for each of the multiple input capacitors connected in series between a pair of input terminals to equally divide the DC input voltage to each input capacitor. A pair of output terminals is connected to the output terminals of each of the multiple DC-DC conversion circuits in parallel. The multiple DC-DC conversion circuits are controlled by a duty cycle control signal to output a target DC voltage. In other words, the DC input voltage input to the control power supply device is equally divided to each of the multiple input capacitors connected in series. The divided voltages to each of the multiple input capacitors are converted into the target DC voltage by the parallel operation of the multiple DC-DC conversion circuits controlled by a duty cycle control signal, and then integrated and output from the pair of output terminals. Therefore, even if the DC input voltage input to the control power supply device is high, since the DC input voltage is divided by the multiple input capacitors and applied to each DC-DC conversion circuit, the control power supply device can be implemented without using high-voltage components. Furthermore, since one control circuit controls multiple DC-DC converter circuits using a single duty cycle control signal, the increase in the number of components can be suppressed compared to the case where multiple control circuits control multiple DC-DC converter circuits separately. Moreover, by using a single control circuit, the duty cycle deviation caused by the skewness of each control circuit, which occurs when multiple control circuits exist, is eliminated.

[0028] Alternatively, the multiple DC-DC conversion circuits may be multiple flyback converters, each comprising: multiple transformers, one end of the primary winding of each transformer being connected to the high-potential terminal of each input capacitor; multiple switching elements, one main terminal of each switching element being connected to the other end of the primary winding of each transformer, and the other main terminal of each switching element being connected to the low-potential terminal of each input capacitor; and multiple main rectifier circuits, each main rectifier circuit rectifying the current output from the primary and secondary windings of the multiple transformers; a signal converter that outputs the isolated duty cycle control signal to the control terminals of the multiple switching elements; a pair of output terminals connected to the respective output terminals of the multiple main rectifier circuits in parallel with each other; and the primary turns ratio of each of the multiple transformers being the same, wherein the primary turns ratio is the turns ratio of the secondary winding relative to the primary winding.

[0029] Based on this structure, a DC-DC conversion circuit consisting of multiple flyback converters is constructed, corresponding to multiple input capacitors. Furthermore, the turns ratio (i.e., the primary turns ratio) of the primary windings of the multiple transformers in these multiple flyback converters is the same, and equal voltage division is applied to the primary windings of these multiple transformers, thus outputting the same output voltage from the primary and secondary windings of the multiple transformers. In this way, the DC-DC conversion circuit consisting of multiple flyback converters converts the applied voltage division into the target DC voltage by operating in parallel, and a pair of output terminals integrates the target DC voltage output from the parallel operation of the multiple DC-DC conversion circuits and outputs it to the outside. Therefore, a control power supply device can be implemented without using expensive, high-voltage-resistant components. Moreover, the flyback converter has a simple structure among various DC-DC conversion circuits, so the number of components in the DC-DC conversion circuit can be reduced. Furthermore, by using a single control circuit, the duty cycle deviation caused by the deviation of each control circuit in the case of multiple control circuits is eliminated.

[0030] Alternatively, the plurality of input capacitors may have substantially the same capacitance as each other.

[0031] This structure allows for a proper equal distribution of voltage across multiple input capacitors.

[0032] Alternatively, the control power supply device may further include: a secondary winding disposed in each of the plurality of transformers, the secondary winding having a predetermined secondary turns ratio relative to the primary winding; a secondary rectifier circuit that connects all the secondary windings in parallel with each other and rectifies the current output from all the secondary windings connected in parallel with each other; and an operating control power supply having a pair of output terminals connected to the output terminal of the secondary rectifier circuit, the pair of output terminals of the operating control power supply being connected to a pair of input terminals of the power supply of the control circuit, the high-potential input terminal of the pair of input terminals of the power supply of the control circuit being connected to the high-potential terminal of the predetermined input capacitor via a starting resistor, and the low-potential input terminal of the pair of input terminals of the power supply of the control circuit being connected to the low-potential terminal of the predetermined input capacitor.

[0033] According to this structure, when the control power supply device is started, power is supplied to the control circuit from a predetermined input capacitor via a starting resistor. During operation after the control power supply device is started, power is mainly supplied from the operating control power supply. Thus, a stable power supply can be provided to the control circuit.

[0034] Alternatively, the control power supply device may be a power supply device used to enable the control circuit of the power converter to operate, and the power converter constitutes the main circuit of the power conversion system including the control power supply device.

[0035] According to this structure, when the main circuit composed of a power converter is high-voltage, the control power supply device can be realized without using high-voltage components.

[0036] Hereinafter, specific embodiments of the present disclosure will be described with reference to the accompanying drawings. Furthermore, in all the drawings below, the same or equivalent elements will be labeled with the same reference numerals, and repeated descriptions will be omitted. Also, the following drawings are for the purpose of explaining the present disclosure, and therefore there may be omissions of elements unrelated to the present disclosure, inaccurate dimensions for exaggeration, simplifications, and inconsistencies in the shapes of corresponding elements in multiple drawings. Furthermore, the present disclosure is not limited to the following embodiments.

[0037] (Implementation Method 1)

[0038] [Structure Overview]

[0039] Figure 1 This is a circuit diagram showing an outline of the structure of the control power supply device 100 according to Embodiment 1 of this disclosure. (Refer to...) Figure 1 The control power supply device 100 has a pair of input terminals 1 and 2, multiple input capacitors Ci1 to Cin, multiple DC-DC conversion circuits COV1 to COVn, a pair of output terminals 3 and 4, a control circuit 5, and a signal converter 6.

[0040] A DC input voltage Vin is applied to a pair of input terminals 1 and 2. Multiple input capacitors Ci1 to Cin are connected in series between the pair of input terminals 1 and 2. The multiple input capacitors Ci1 to Cin distribute the DC input voltage Vin equally among themselves. The input terminals of multiple DC-DC converters COV1 to COVn are respectively connected between the two ends of the multiple input capacitors Ci1 to Cin, and the multiple DC-DC converters COV1 to COVn are each controlled by a duty cycle control signal Sc. A pair of output terminals 3 and 4 are connected to the output terminals of the multiple DC-DC converters COV1 to COVn in a manner that connects them in parallel. The control circuit 5 receives power from a designated input capacitor Ci1, which is one of the multiple input capacitors Ci1 to Cin, and outputs a duty cycle control signal Sc with a duty cycle corresponding to the target DC voltage Vt. The signal converter 6 converts the duty cycle control signal Sc output from the control circuit 5 into a duty cycle control signal Sc that is insulated from the duty cycle control signal Sc, and inputs the insulated duty cycle control signal Sc to multiple DC-DC conversion circuits COV1 to COVn.

[0041] The detailed structure of each element of the control power supply device 100 of this embodiment 1 will be described in the following description of the specific structure of the control power supply device 100.

[0042] In this control power supply device 100, DC-DC conversion circuits COV1 to COVn are respectively provided for multiple input capacitors Ci1 to Cin, which are connected in series between a pair of input terminals 1 and 2 to equally distribute the DC input voltage Vin to each input capacitor Ci1 to Cin. A pair of output terminals 3 and 4 are connected to the output terminals of each of the multiple DC-DC conversion circuits COV1 to COVn in a manner that connects them in parallel. The multiple DC-DC conversion circuits COV1 to COVn are controlled by a duty cycle control signal Sc corresponding to the target DC voltage Vt to output the target DC voltage Vt. In other words, the DC input voltage Vin input to the control power supply device 100 is equally divided among multiple input capacitors Ci1 to Cin connected in series. The voltages Vd1 to Vdn divided among these multiple input capacitors Ci1 to Cin are then converted into the target DC voltage Vt by the parallel operation of multiple DC-DC conversion circuits COV1 to COVn controlled by a duty cycle control signal Sc. This Vt is then integrated by a pair of output terminals 3 and 4 and output as the DC output voltage Vout from these terminals. Thus, even if the DC input voltage Vin input to the control power supply device 100 is high, since the DC input voltage Vin is divided among the multiple input capacitors Ci1 to Cin and applied to each DC-DC conversion circuit COV1 to COVn, the control power supply device 100 can be implemented without using expensive, high-voltage-resistant components. Furthermore, since a control circuit 5 uses a duty cycle control signal Sc to control multiple DC-DC conversion circuits COV1 to COVn, it can suppress the increase in the number of components compared to the case where multiple control circuits control multiple DC-DC conversion circuits separately.

[0043] Furthermore, by using a single control circuit, the deviation in duty cycle caused by the deviation of each control circuit, which occurs when multiple control circuits exist, is eliminated.

[0044] [Specific structural examples]

[0045] Figure 2 It is shown Figure 1 A circuit diagram illustrating an example of the specific structure of the control power supply device 100. (Refer to...) Figure 2In this structural example, the multiple DC-DC conversion circuits COV1 to COVn are each composed of multiple flyback converters. Furthermore, feedback control is performed on the DC output voltage Vout. The control power supply unit 100 also includes a starting resistor element Rs and an operating control power supply 7. The specific structure of the control power supply unit 100 will be described in detail below.

[0046] exist Figure 2 In this device, the control power supply 100 includes a pair of input terminals 1 and 2, multiple input capacitors Ci1 to Cin, multiple DC-DC conversion circuits COV1 to COVn, a pair of output terminals 3 and 4, a control circuit 5, a signal converter 6, and a control power supply 7 for operation.

[0047] <Purpose of Control Power Supply Device 100>

[0048] The application of the control power supply device 100 is not particularly limited. However, its primary application is as a power supply device that enables the operation of the control circuit of a power converter in a power conversion system, which constitutes the main circuit of the power conversion system. Examples of power conversion systems in which the power converter constitutes the main circuit include, for example, DC power supply devices using DC-DC converters and energy storage converters (PCS).

[0049]

[0050] An external DC input voltage Vin is applied to a pair of input terminals 1 and 2. The power source for the DC input voltage Vin is not particularly limited. Examples of such a power source include those corresponding to the uses of the control power supply device 100 described above.

[0051] <Multiple input capacitors Ci1~Cin>

[0052] Multiple input capacitors Ci1 to Cin are connected in series between a pair of input terminals 1 and 2. The DC input voltage Vin is equally divided among the input capacitors Ci1 to Cin through capacitive voltage division. Therefore, the multiple input capacitors Ci1 to Cin essentially have the same capacitance. The capacitance and number of the multiple input capacitors Ci1 to Cin are determined through calculation, simulation, experimentation, and empirical rules, taking into account the DC input voltage Vin, the voltages applied to each DC-DC converter circuit COV1 to COVn (i.e., the voltage divider voltages Vd1 to Vdn), and the target DC voltage Vt.

[0053] Here, in the specification and claims of this application, "equally divided voltage" is defined as a voltage divided into voltages with an error range of ±5% relative to a completely equal divided voltage. Furthermore, "the plurality of input capacitors Ci1 to Cin substantially have the same capacitance" is defined as the plurality of input capacitors Ci1 to Cin having an error capacitance range of ±20% relative to an identical capacitance. This definition takes into account that the capacitance error of commercially available capacitors is generally around ±10%, with a maximum of around ±20%.

[0054] There are no particular restrictions on the specifications of the multiple input capacitors Ci1 to Cin. For example, commercially available capacitors can be used as the multiple input capacitors Ci1 to Cin.

[0055] {Specified input capacitor}

[0056] Any one of the multiple input capacitors Ci1 to Cin is designated as the "prescribed input capacitor". Here, the "prescribed input capacitor" is designated as input capacitor Ci1. Corresponding to the input capacitor Ci1 as the "prescribed input capacitor", a control circuit 5, a signal converter 6 as an element associated with the control of the control circuit 5, an output voltage feedback circuit 20, and a primary-side current sensing resistor element Ris are provided. These elements will be described in turn below.

[0057] <Multiple DC-DC converter circuits COV1~COVn>

[0058] The input terminals of multiple DC-DC converter circuits COV1 to COVn are respectively connected to the two ends of multiple input capacitors Ci1 to Cin.

[0059] Examples of DC-DC converters COV1 to COVn include flyback converters, half-bridge DC-DC converters, and full-bridge DC-DC converters. Here, the DC-DC converters COV1 to COVn are configured as flyback converters. Embodiment 2 shows a configuration where the DC-DC converters COV1 to COVn are configured as half-bridge or full-bridge DC-DC converters.

[0060] The DC-DC conversion circuit COV1~COVn, which consists of multiple flyback converters, includes multiple transformers TF1~TFn, multiple switching elements Q1~Qn, and multiple main rectifier circuits RCT1~RCTn.

[0061] {Multiple transformers TF1~TFn}

[0062] One end of the primary windings Wp1 to Wpn of each of the multiple transformers TF1 to TFn is connected to the high-potential terminals of multiple input capacitors Ci1 to Cin. Furthermore, buffer circuits Sv1 to Svn are connected between the two ends of the primary windings Wp1 to Wpn of each of the multiple transformers TF1 to TFn. The turns ratio (nm) of the primary windings Wsm1 to Wsn of each of the multiple transformers TF1 to TFn relative to the primary windings Wp1 to Wpn is the same for all of them. The specifications of the multiple transformers TF1 to TFn are not particularly limited. For example, commercially available transformers can be used as the multiple transformers TF1 to TFn.

[0063] {Multiple switching elements Q1~Qn}

[0064] Switching elements Q1 to Qn have a first main terminal T1, a second main terminal T2, and a control terminal Tc. Each of the multiple switching elements Q1 to Qn is connected at its first main terminal (one main terminal) T1 to the other end of the primary windings Wp1 to Wpn of a plurality of transformers TF1 to TFn, and at its second main terminal (another main terminal) T2 to the low-potential terminal of a plurality of input capacitors Ci1 to Cin. However, the second main terminal T2 of the switching element Q1 corresponding to the input capacitor Ci1, which is a specified input capacitor, is connected to the low-potential terminal of the input capacitor Ci1 via a primary-side current sensing resistor element Ris.

[0065] The switching elements Q1 to Qn are, for example, MOSFETs, bipolar transistors, IGBTs, etc. When Q1 to Qn are N-channel MOSFETs, the first main terminal, the second main terminal, and the control terminal are the drain, source, and gate, respectively. When Q1 to Qn are P-channel MOSFETs, the first main terminal, the second main terminal, and the control terminal are the source, the drain, and the control terminal, respectively. When Q1 to Qn are npn bipolar transistors, the first main terminal, the second main terminal, and the control terminal are the collector, the emitter, and the base, respectively. When Q1 to Qn are pnp bipolar transistors, the first main terminal, the second main terminal, and the control terminal are the emitter, the collector, and the base, respectively. When the switching elements Q1 to Qn are N-channel IGBTs, the first main terminal, the second main terminal, and the control terminal are the collector, the emitter, and the gate, respectively. When the switching elements Q1 to Qn are P-channel IGBTs, the first main terminal, the second main terminal, and the control terminal are the emitter, the collector, and the gate, respectively.

[0066] Here, the switching elements Q1 to Qn are N-channel MOSFETs. The control terminals (gates) Tc of the switching elements Q1 to Qn are connected to the high-potential output terminals of the signal converter 6 via gate resistors Rg. The control terminals (gates) Tc of the switching elements Q1 to Qn are connected to the second main terminal (source) via gate-source resistors Rgs. The second main terminal (source) T2 of the switching elements Q1 to Qn is connected to the low-potential output terminals of the signal converter 6.

[0067] {Multiple main rectifier circuits RCT1~RCTn}

[0068] Multiple main rectifier circuits RCT1 to RCTn are connected to the two ends of the primary and secondary windings Wsm1 to Wsmn of multiple transformers TF1 to TFn at a pair of input terminals, respectively. Each of the multiple main rectifier circuits RCT1 to RCTn rectifies the current output from the primary and secondary windings Wsm1 to Wsmn of the corresponding transformers TF1 to TFn. The multiple main rectifier circuits RCT1 to RCTn can be constructed from known rectifier circuits, therefore their description is omitted. Here, the multiple main rectifier circuits RCT1 to RCTn are constructed from diodes whose anodes are connected to one end of the primary and secondary windings Wsm1 to Wsmn of the transformers TF1 to TFn, respectively.

[0069]

[0070] A pair of output terminals 3 and 4 are connected to the output terminals of each of the multiple main rectifier circuits RCT1 to RCTn in a manner that connects them in parallel. Specifically, the high-potential output terminal 3 of the pair of output terminals 3 and 4 is connected to the cathode of the diodes constituting the multiple main rectifier circuits RCT1 to RCTn, and the low-potential output terminal 4 of the pair of output terminals 3 and 4 is connected to the other end of the primary and secondary windings Wsm1 to Wsmn of the multiple transformers TF1 to TFn.

[0071] An output capacitor Co is connected between a pair of output terminals 3 and 4. The output capacitor Co smooths the voltage output from the multiple main rectifier circuits RCT1 to RCTn. Alternatively, instead of the output capacitor Co, multiple smoothing capacitors can be connected between the cathodes of the diodes constituting the multiple main rectifier circuits RCT1 to RCTn and the other ends of the primary and secondary windings Wsm1 to Wsmn of the multiple transformers TF1 to TFn.

[0072] <Control Circuit 5>

[0073] The control circuit 5 receives power from a specified input capacitor Ci1, which is one of a plurality of input capacitors Ci1 to Cin, and the operation control power supply 7 described later, and outputs a duty cycle control signal Sc having a duty cycle corresponding to the target DC voltage Vt.

[0074] {Connection Relationship}

[0075] Specifically, control circuit 5 connects the high-potential input terminal TL1 to the high-potential terminal of a specified input capacitor Ci1 via a starting resistor element Rs, and connects the low-potential input terminal TL4 to the low-potential terminal of the specified input capacitor Ci1. Furthermore, the high-potential input terminal TL1 and the low-potential input terminal TL4 of control circuit 5 are connected to the high-potential output terminal 11 and the low-potential output terminal 12 of the operating control power supply 7, respectively. The low-potential input terminal TL4 is grounded (see reference). Figure 3 The output terminals TL5 and TL6 of control circuit 5 are connected to the input terminals of signal converter 6. The voltage signal input terminals TL2 and TL3 of control circuit 5 are connected to the output terminals of output voltage feedback circuit 20. The current signal input terminal TL7 of control circuit 5 is connected to the high-potential terminal of primary-side current sensing resistor element Ris.

[0076] {action}

[0077] When the control power supply device 100 is started, the control circuit 5 receives power from the specified input capacitor Ci1 via the starting resistor element Rs. When the multiple DC-DC conversion circuits COV1 to COVn are turned on, it receives power from both the input capacitor Ci1 and the operating control power supply 7.

[0078] The input terminal of the output voltage feedback circuit 20 is connected to a pair of output terminals 3 and 4. The detection signal of the DC output voltage Vout detected by the output voltage feedback circuit 20 is input to a pair of voltage signal input terminals TL2 and TL3 of the control circuit 5 via an opto-isolator (e.g., an optocoupler) 21. Based on the detection signal of the DC output voltage Vout, the control circuit 5 generates a duty cycle control signal Sc that makes the DC output voltage Vout become the target DC voltage Vt, and outputs it to the signal converter 6. Based on this, the control circuit 5 controls the plurality of DC-DC conversion circuits COV1 to COVn, so that the plurality of DC-DC conversion circuits COV1 to COVn output the target DC voltage Vt.

[0079] Furthermore, the control circuit 5 performs gate blocking in the event of an overcurrent, based on the detection signal of the primary side current Ip detected by the primary side current sensing resistor element Ris.

[0080] {structure}

[0081] The control circuit 5 is, for example, composed of an arithmetic logic unit (ALU) with a processor and a memory. The memory stores a control program that controls the aforementioned actions of the control circuit 5. The processor reads and executes the control program, and the control circuit 5 performs the aforementioned actions.

[0082] Figure 3 It is shown Figure 2 A circuit diagram illustrating an example of the structure of control circuit 5. (Refer to...) Figure 3 Here, control circuit 5 is composed of a circuit containing control IC 31, which is a dedicated control chip containing the aforementioned arithmetic unit. Control IC 31 has Vcc, Vref, RT / CT, Vfb, GND, OUT, and Is terminals. Vcc is a high-potential power supply terminal, constituting the high-potential input terminal TL1 of control circuit 5. Vref is a reference voltage terminal, constituting the high-potential voltage signal input terminal TL2 of the pair of voltage signal input terminals TL2 and TL3 of control circuit 5. RT / CT is a terminal for setting the switching frequency, grounded via a capacitor, and connected to the Vref terminal via a resistor. Vfb is an output voltage feedback terminal, connected to the low-potential voltage signal input terminal TL3 of the pair of voltage signal input terminals TL2 and TL3 via a resistor. The low-potential voltage signal input terminal TL3 is grounded via a resistor. GND is grounded. GND is connected to the low-potential input terminal TL4 of control circuit 5 and the low-potential output terminal TL5 of the pair of output terminals TL5 and TL6. The OUT terminal is an output terminal, connected to the high-potential output terminal TL6 of the pair of output terminals TL5 and TL6 of the control circuit 5. The Is terminal is a current sensing terminal, grounded via a capacitor. Furthermore, the Is terminal is connected to the current signal input terminal TL7 of the control circuit 5 via a resistor. With this connection, the control IC 31 performs the operation of the control circuit 5 described above.

[0083] <Signal Converter 6>

[0084] The signal converter 6 converts the duty cycle control signal Sc output from the control circuit 5 into a duty cycle control signal Sc that is insulated from the duty cycle control signal Sc, and inputs the insulated duty cycle control signal Sc to multiple DC-DC conversion circuits COV1 to COVn.

[0085] Specifically, the signal converter 6 converts the duty cycle control signal Sc output from the control circuit 5 into an isolated duty cycle control signal Sc, and inputs the isolated duty cycle control signal Sc to the control terminals Tc of the multiple switching elements Q1 to Qn of the multiple DC-DC conversion circuits COV1 to COVn via the gate resistor element Rg.

[0086] The signal converter 6 is composed of isolators such as insulated transformers and optocouplers. Here, the signal converter 6 is composed of an insulated transformer.

[0087] <Operating Control Power Supply 7>

[0088] The operating control power supply 7 has multiple secondary windings Wss1 to Wssn, a secondary rectifier circuit 8, a high-potential output terminal 11, and a low-potential output terminal 12. These multiple secondary windings Wss1 to Wssn are respectively disposed in each of the multiple transformers TF1 to TFn. Each of the multiple secondary windings Wss1 to Wssn has a specified secondary turns ratio ns relative to the primary winding of each of the multiple transformers TF1 to TFn.

[0089] The secondary rectifier circuit 8 connects all secondary windings Wss1 to Wssn in parallel with each other, and rectifies the current output from all the secondary windings Wss1 to Wssn connected in parallel with each other. The secondary rectifier circuit 8 can be constructed using a known rectifier circuit. Here, the secondary rectifier circuit is composed of diodes connected to one end of the secondary windings Wss1 to Wssn of the multiple transformers TF1 to TFn at their anodes, a first wiring WRG1 connecting the cathodes of all diodes in parallel with each other, and a second wiring WRG2 connecting the other ends of the secondary windings Wss1 to Wssn of the multiple transformers TF1 to TFn in parallel. Furthermore, the high-potential output terminal 11 of the operation control power supply 7 is connected to the first wiring WRG1. Furthermore, the low-potential output terminal 12 of the operation control power supply 7 is connected to the second wiring WRG2.

[0090] The control power supply 7 configured in this way rectifies the alternating current obtained from the multiple secondary windings Wss1 to Wssn of each of the multiple transformers TF1 to TFn after the control power supply device 100 is started, and provides the DC voltage obtained by the rectification to the control circuit 5.

[0091] [Operation of the control power supply device 100]

[0092] Next, refer to Figure 2 The operation of the control power supply device 100 configured as described above will be explained. Furthermore, the voltage drop caused by the primary-side current sensing resistor element Ris will be ignored below.

[0093] When a DC input voltage Vin is applied to a pair of input terminals 1 and 2, the DC input voltage Vin is equally divided by multiple input capacitors Ci1 to Cin, and the multiple divided voltages Vd1 to Vdn are respectively applied to multiple DC-DC conversion circuits COV1 to COVn. In the multiple DC-DC conversion circuits COV1 to COVn, the multiple divided voltages Vd1 to Vdn are respectively applied between one end of the primary winding Wp1 to Wpn of the multiple transformers TF1 to TFn and the second main terminal T2 of the switching elements Q1 to Qn.

[0094] On the other hand, control circuit 5 receives power from input capacitor Ci1, which is a predetermined input capacitor, via starting resistor element Rs, and outputs a duty cycle control signal Sc with a duty cycle corresponding to the target DC voltage Vt to signal converter 6. Signal converter 6 converts the duty cycle control signal Sc into an isolated duty cycle control signal Sc, and inputs the isolated duty cycle control signal Sc to the control terminals Tc of the switching elements Q1 to Qn of multiple DC-DC conversion circuits COV1 to COVn. Thus, the multiple switching elements Q1 to Qn are in the on state and the off state respectively, corresponding to the on period (high level period here) and the off period (low level period here) of the isolated duty cycle control signal Sc. As a result, an AC voltage corresponding to the target DC voltage Vt is induced in the primary and secondary windings Wsm1 to Wsmn of multiple transformers TF1 to TFn, and the current generated by the induced AC voltage is rectified by multiple main rectifier circuits RCT1 to RCTn. The DC voltage obtained by rectification by the multiple main rectifier circuits RCT1 to RCTn is integrated by a pair of output terminals 3 and 4 and smoothed by the output capacitor Co, thus outputting as the DC output voltage Vout from the pair of output terminals 3 and 4. At this time, the detection signal of the DC output voltage Vout is input to the control circuit 5 via the output voltage feedback circuit 20. The control circuit 5 generates a duty cycle control signal that makes the DC output voltage Vout become the target DC voltage Vt based on the detection signal of the DC output voltage Vout. In this way, the control circuit 5 feeds back and controls the DC output voltage Vout to the target DC voltage Vt.

[0095] On the other hand, after the control power supply device 100 is started, when the operation control power supply 7 is turned on, power is also supplied from the operation control power supply 7 to the control circuit 5.

[0096] [Effects]

[0097] According to such a control power supply device 100, a DC-DC conversion circuit COV1 to COVn composed of multiple flyback converters is constructed corresponding to multiple input capacitors Ci1 to Cin. Furthermore, the turns ratio (nm) of the primary and secondary windings Wsm1 to Wsmn of the multiple transformers TF1 to TFn of these multiple flyback converters relative to the primary windings Wp1 to Wpn is the same for each other, and equal voltage division voltages Vd1 to Vdn are applied to the primary windings Wp1 to Wpn of these multiple transformers TF1 to TFn. Therefore, the same AC voltage is output from the primary and secondary windings Wsm1 to Wsmn of the multiple transformers TF1 to TFn. This AC voltage is output as a DC output voltage Vout with a target DC voltage Vt through the action of multiple main rectifier circuits RCT1 to RCTn and a pair of output terminals 3 and 4. In this way, the DC-DC conversion circuits COV1 to COVn, which consist of multiple flyback converters, convert the applied voltages into target DC voltages Vt by operating in parallel. A pair of output terminals 3 and 4 integrate the target DC voltages Vt output by the parallel operation of the multiple DC-DC conversion circuits COV1 to COVn and output them to the outside.

[0098] Therefore, the control power supply device 100 can be implemented without using high-voltage components. Furthermore, the flyback converter has a simple structure in various DC-DC conversion circuits, so the number of components in the DC-DC conversion circuit can be reduced.

[0099] Furthermore, when the control power supply device 100 is a power supply device used to operate the control circuit of a power converter that constitutes the main circuit of a power conversion system including the control power supply device 100, even if the main circuit constituted by the power converter is high voltage, the control power supply device 100 can be implemented without using high voltage-resistant components.

[0100] [Example]

[0101] As an embodiment of the control power supply device 100 of this Embodiment 1, an actual circuit was fabricated. In this embodiment, the control power supply device 100 is based on... Figure 2 This is a case where the number of input capacitors Ci1 to Cin is 2.

[0102] Figure 4 This is a waveform diagram showing the operation of an embodiment of the control power supply device 100 of Embodiment 1. Figure 4 This diagram is obtained by tracking actual measured data from the circuit. Figure 4In the diagram, the horizontal axis represents time (s), and the vertical axis represents voltage (V) or current (A). Label WF1 represents the waveform of the voltage Vd1 across input capacitor Ci1. Label WF2 represents the waveform of the voltage Vd2 across input capacitor Ci2. Label WF3 represents the waveform of the primary-side current Ip of the DC-DC converter circuit COV1. Label WF4 represents the waveform of the voltage Vds across switching element Q1. Label WF5 represents the waveform of the DC output voltage Vout. Label WF6 represents the waveform of the DC input voltage Vcc of control circuit 5.

[0103] Reference Figure 4 From the waveforms WF1 and WF2 of the voltage divider voltages Vd1 and Vd2, it can be seen that the voltage divider voltage Vd1 of the input capacitor Ci1 is approximately the same as the voltage divider voltage Vd2 of the input capacitor Ci2, and the DC input voltage Vin is divided approximately equally. From the waveforms WF3 of the primary side current Ip of the DC-DC converter circuit COV1 and WF4 of the voltage Vds across the switching element Q1, it can be seen that the switching element Q1 is switched on and off according to the duty cycle control signal Sc, thus generating a pulsed voltage Vds across the switching element Q1 corresponding to the duty cycle of the duty cycle control signal Sc. From the waveform WF5 of the DC output voltage Vout, it can be seen that the pulsed voltage Vds is transformed, DCized, and smoothed. In other words, from the waveforms WF3 of the primary side current Ip, WF4 of the voltage Vds, and WF5 of the DC output voltage Vout, it can be seen that the DC-DC converter circuit COV1 operates as a flyback converter. As can be seen from the waveform WF6 of the DC input voltage Vcc of control circuit 5, a stable DC input voltage Vcc is provided to control circuit 5.

[0104] The above content confirms that the control power supply device 100 of Embodiment 1 is practical.

[0105] (Implementation Method 2)

[0106] The control power supply device of Embodiment 2 of this disclosure is in Figure 2 The multiple DC-DC conversion circuits COV1 to COVn are respectively composed of half-bridge DC-DC converters or full-bridge DC-DC converters. Other structures are similar to... Figure 2 The multiple DC-DC conversion circuits COV1 to COVn are identical.

[0107] Half-bridge or full-bridge DC-DC converters are simply... Figure 2 In the DC-DC conversion circuit COV1~COVn, the primary side of transformers TF1~TFn changes from a single switching element to a half-bridge inverter or a full-bridge inverter. Therefore, those skilled in the art can, based on Figure 2The control power supply device of Embodiment 2 is constructed using DC-DC conversion circuits COV1 to COVn. Therefore, further detailed descriptions are omitted.

[0108] The same effect as the control power supply device 100 in embodiment 1 can be obtained by using the control power supply device of embodiment 2.

[0109] (Other implementation methods)

[0110] In either embodiment 1 or embodiment 2, feedforward control of the DC output voltage Vout can be used instead of feedback control.

[0111] In either embodiment 1 or embodiment 2, the operating control power supply 7 may be omitted.

[0112] Based on the above description, many improvements or other implementations will be apparent to those skilled in the art. Therefore, the above description should be interpreted as merely illustrative.

[0113] [Industry Applicability]

[0114] The control power supply device of the present invention is useful as a control power supply device that can be implemented without using high-voltage components.

Claims

1. A control power supply device, comprising: A pair of input terminals to which a DC input voltage is applied; Multiple input capacitors are connected in series between the pair of input terminals to distribute the DC input voltage equally among the input capacitors. Multiple DC-DC conversion circuits, each of which has its input terminal connected between the two ends of multiple input capacitors, and each of which is controlled by a duty cycle control signal; A pair of output terminals, which are connected to the output terminals of the plurality of DC-DC converter circuits in such a way that the plurality of DC-DC converter circuits are connected in parallel with each other; A control circuit that receives power from a predetermined input capacitor, which is one of the plurality of input capacitors, and outputs a duty cycle control signal having a duty cycle corresponding to a target DC voltage. as well as A signal converter that converts the duty cycle control signal output from the control circuit into a duty cycle control signal that is insulated from the duty cycle control signal, and inputs the insulated duty cycle control signal to the plurality of DC-DC conversion circuits.

2. The control power supply device according to claim 1, wherein, The multiple DC-DC conversion circuits are multiple flyback converters. The plurality of flyback converters include: Multiple transformers, one end of the primary winding of each of the multiple transformers being connected to the high-potential terminal of the multiple input capacitors respectively; Multiple switching elements, each having a main terminal connected to the other end of the primary winding of the multiple transformers, and another main terminal connected to the low-potential terminal of the multiple input capacitors; as well as Multiple main rectifier circuits, each of which rectifies the current output from the primary and secondary windings of the multiple transformers. The signal converter is a signal converter that outputs the insulated duty cycle control signal to the control terminals of the plurality of switching elements. The pair of output terminals are connected to the output terminals of each of the plurality of main rectifier circuits in such a manner that the plurality of main rectifier circuits are connected in parallel with each other. The primary turns ratio of each of the plurality of transformers is the same as that of the secondary windings relative to the primary windings.

3. The control power supply device according to claim 1 or 2, wherein, The plurality of input capacitors have substantially the same capacitance as each other.

4. The control power supply device according to claim 1 or 2, wherein, The control power supply device also has: A secondary winding is provided in each of the plurality of transformers, the secondary winding having a specified secondary turns ratio relative to the primary winding; A secondary rectifier circuit that connects all the secondary windings in parallel with each other and rectifies the current output from all the secondary windings connected in parallel with each other; as well as The operating control power supply has a pair of output terminals connected to the output terminal of the auxiliary rectifier circuit. The pair of output terminals of the operating control power supply are connected to the pair of input terminals of the power supply of the control circuit. The high-potential input terminal of the power supply of the control circuit is connected to the high-potential terminal of the specified input capacitor via a start-up resistor, and the low-potential input terminal of the power supply of the control circuit is connected to the low-potential terminal of the specified input capacitor.

5. The control power supply device according to claim 1 or 2, wherein, The control power supply device is a power supply device used to enable the control circuit of the power converter to operate, and the power converter constitutes the main circuit of the power conversion system including the control power supply device.

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