Multiple-input dc conversion system

Abstract

The utility model discloses a kind of multi-input direct current conversion systems, the multi-input direct current conversion system includes N input control unit, direct current conversion control unit and MCU module;Direct current conversion control unit includes the direct current conversion module being connected with MCU module, total input voltage sampling circuit and total output voltage sampling circuit, total input voltage sampling circuit and total output voltage sampling circuit are used for respectively collecting the input voltage and output voltage of direct current conversion module;The output end of N input control unit is connected with the input end of direct current conversion module, and MCU module is connected with N input control unit respectively and carries out on-off control respectively.The utility model has the advantages of low cost, and it is convenient to carry out coordinated control.

Description

Technical Field

[0001] This utility model relates to the field of power electronics, and in particular to a multi-input DC-DC converter system. Background Technology

[0002] DC-DC converters play a vital role in the power systems of many existing devices. They enable energy transfer between different voltages, facilitating power supply to various loads or charging of batteries.

[0003] In many devices, it is often necessary to convert multiple different DC voltages to the same DC voltage for output. For example, in the power system of a motorhome, when the solar power generation device or the vehicle generator is generating enough power, the two DC voltages output by the solar power generation device and the vehicle generator need to be converted by a DC-DC converter to charge the backup battery. The backup battery stores the energy and then supplies power to the motorhome loads.

[0004] However, currently, for situations where multiple DC input voltages need to be converted into the same DC output voltage, multiple DC converters or DC conversion circuits are generally set up directly, with each DC converter or DC conversion circuit converting one DC input voltage. This direct conversion method is costly, occupies a large volume, and it is not easy to coordinate and control different DC converters.

[0005] In view of the above problems, it is necessary to study a multi-input DC-DC converter system that is low in cost and easy to coordinate and control. Utility Model Content

[0006] The purpose of this invention is to provide a multi-input DC-DC converter system that is easy to control and has low cost.

[0007] To achieve the above objectives, the solution of this utility model is: A multi-input DC-DC converter system includes N input control units, a DC-DC converter control unit, and an MCU module. The DC-DC converter control unit includes a DC-DC converter module, a total input voltage sampling circuit, and a total output voltage sampling circuit. The total input voltage sampling circuit is connected to the DC-DC converter module and is used to acquire the input voltage of the DC-DC converter module. The total output voltage sampling circuit is connected to the DC-DC converter module and is used to acquire the output voltage of the DC-DC converter module. The output terminals of the total input voltage sampling circuit and the total output voltage sampling circuit are connected to the MCU module. The DC-DC converter module is connected to the MCU module, and the MCU module can control the output voltage of the DC-DC converter module. The N input control units are divided into the first input control unit to the Nth input control unit. The i-th input control unit includes the i-th input switch circuit and the i-th input voltage sampling circuit. The input terminal of the i-th input switch circuit is used to connect to the DC input voltage, and the output terminal of the i-th input switch circuit can be connected to the input terminal of the DC-DC converter module via a straight bus. The control terminal of the i-th input switch circuit is connected to the MCU module. The i-th input voltage sampling circuit is connected to the i-th input switch circuit and is used to acquire the input voltage of the i-th input switch circuit. The output terminal of the i-th input voltage sampling circuit is connected to the MCU module. i is an integer from 1 to N.

[0008] The i-th input control unit also includes an i-th power supply control circuit for providing drive power VDD-i to the i-th input switch circuit. The control terminal of the i-th power supply control circuit is connected to the MCU module, and the MCU module controls whether the i-th power supply control circuit outputs drive power VDD-i.

[0009] The i-th input switch circuit includes an i-th optocoupler isolation circuit, an i-th amplifier circuit, and an i-th electronic switch circuit. The input terminal of the i-th optocoupler isolation circuit is connected to the control terminal of the i-th input switch circuit. The input terminal of the i-th optocoupler isolation circuit is connected to the input terminal of the i-th amplifier circuit. The output terminal of the i-th optocoupler isolation circuit is connected to the input terminal of the i-th amplifier circuit. The output terminal of the i-th amplifier circuit is connected to the drive power supply VDD-i. The input terminal and output terminal of the i-th electronic switch circuit are respectively connected to the input terminal and output terminal of the i-th input switch circuit.

[0010] The i-th optocoupler isolation circuit includes resistors R11-i, R12-i, R13-i, R14-i, R15-i, transistor Q10-i, and optocoupler OC11-i. The first terminal of resistor R11-i is connected to the input terminal of the i-th optocoupler isolation circuit. The second terminal of resistor R11-i is connected to the first terminal of resistor R12-i and the base of transistor Q10-i. The second terminal of resistor R12-i and the emitter of transistor Q10-i are connected to ground. The collector of 10-i is connected to the negative terminal of the input side of optocoupler OC11-i. The positive terminal of the input side of optocoupler OC11-i is connected to the first terminal of resistor R13-i. The second terminal of resistor R13-i is connected to the control power supply VCC. The positive terminal of the output side of optocoupler OC11-i is connected to the drive power supply VDD-i through resistor R14-i. The negative terminal of the output side of optocoupler OC11-i and the first terminal of resistor R15-i are connected to the output terminal of the i-th optocoupler circuit. The second terminal of resistor R15-i is connected to the second ground.

[0011] The i-th amplifier circuit includes resistors R16-i and R17-i, transistors Q11-i and Q12-i. The bases of transistors Q11-i and Q12-i are connected to the input terminal of the i-th amplifier circuit. The collector of transistor Q11-i is connected to the power supply terminal of the i-th amplifier circuit. The emitters of transistors Q11-i and Q12-i are connected to the first terminals of resistors R16-i and R17-i. The collector of transistor Q12-i and the second terminal of resistor R17-i are connected to a second ground. The second terminal of resistor R16-i is connected to the output terminal of the i-th amplifier circuit.

[0012] The i-th electronic switch circuit includes MOSFETs M11-i and M12-i. The gates of MOSFETs M11-i and M12-i are connected to the control terminal of the i-th electronic switch circuit. The source of MOSFET M11-i is connected to the input terminal of the i-th electronic switch circuit. The drain of MOSFET M11-i is connected to the source of MOSFET M12-i. The drain of MOSFET M12-i is connected to the output terminal of the i-th electronic switch circuit.

[0013] The i-th power supply control circuit includes resistors R41-i, R42-i, R43-i, R44-i, R45-i, capacitors C41-i and C42-i, Zener diodes D41-i and D42-i, transistors Q41-i, Q42-i, and Q43-i. The first terminal of resistor R41-i is connected to the control terminal of the i-th power supply control circuit. The second terminal of resistor R41-i and the first terminal of resistor R42-i are connected to the base of transistor Q41-i. The emitter of transistor Q41-i and the second terminal of resistor R42-i are connected to ground. The collector of transistor Q41-i and the first terminal of resistor R44-i are connected to the bases of transistors Q42-i and Q43-i. The second terminal of resistor R44-i is connected to... The first terminal of resistor R43-i is connected to the collector of transistor Q42-i. The second terminal of resistor R43-i is connected to the control power supply VCC. The emitter of transistor Q42-i and the emitter of transistor Q43-i are connected to the first terminal of resistor R45-i. The collector of transistor Q43-i is connected to the first ground. The second terminal of resistor R45-i is connected to the first terminal of capacitor C41-i. The second terminal of capacitor C41-i is connected to the positive terminal of Zener diode D41-i and the negative terminal of Zener diode D42-i. The negative terminal of Zener diode D41-i and the first terminal of capacitor C42-i are connected to the output terminal of the i-th power supply control circuit. The output terminal of the i-th power supply control circuit is used to output the drive power supply VDD-i. The positive terminal of Zener diode D42-i and the second terminal of capacitor C42-i are connected to the input terminal of the i-th input switch circuit.

[0014] The i-th input voltage sampling circuit includes resistors R21-i and R22-i. The first end of resistor R21-i is connected to the input terminal of the i-th input voltage sampling circuit, and the input terminal of the i-th input voltage sampling circuit is connected to the input terminal of the i-th input switch circuit. The second end of resistor R21-i and the first end of resistor R22-i are connected to the output terminal of the i-th input voltage sampling circuit, and the second end of resistor R22-i is connected to the first ground.

[0015] The i-th input control unit also includes an i-th input current sampling circuit, which is connected to the i-th input switch circuit and used to collect the input current of the i-th input switch circuit. The output of the i-th input current sampling circuit is connected to the MCU module.

[0016] The input terminal of the i-th input switch circuit is connected in series with a resistor R0-i; the i-th input current sampling circuit includes resistors R31-i, R32-i, R33-i, R34-i, R35-i, R36-i and operational amplifier OP31-i. The first terminal of resistor R31-i is connected to the first terminal of resistor R0-i, and the second terminal of resistor R31-i and the first terminal of resistor R33-i are connected to the inverting input terminal of operational amplifier OP31-i. The first terminal of resistor R32-i... The second terminal of resistor R0-i is connected to the first terminal of resistor R32-i. The second terminal of resistor R34-i and the first terminal of resistor R34-i are connected to the first ground. The second terminal of resistor R33-i and the first terminal of resistor R35-i are connected to the output terminal of op-amp OP31-i. The second terminal of resistor R35-i and the first terminal of resistor R36-i are connected to the output terminal of the i-th input current sampling circuit. The first terminal of resistor R36-i is connected to the first ground.

[0017] The total input voltage sampling circuit includes resistors R51-i and R52-i. The first end of resistor R51-i is connected to the input terminal of the total input voltage sampling circuit, which is connected to the input terminal of the DC-DC converter module. The second end of resistor R51-i and the first end of resistor R52-i are connected to the output terminal of the total input voltage sampling circuit. The second end of resistor R52-i is connected to the first ground. The total output voltage sampling circuit includes resistors R61-i and R62-i. The first end of resistor R61-i is connected to the input terminal of the total output voltage sampling circuit, which is connected to the output terminal of the DC-DC converter module. The second end of resistor R61-i and the first end of resistor R62-i are connected to the output terminal of the total output voltage sampling circuit. The second end of resistor R62-i is connected to the first ground.

[0018] By adopting the above scheme, this utility model receives different DC input voltages through multiple input control units and performs DC conversion through a single DC conversion control unit, resulting in a simpler structure and lower cost. Furthermore, this utility model uses an MCU module to coordinate and control each input control unit and the DC conversion control unit, ensuring the normal operation of the entire multi-input DC conversion system. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the principle of this utility model.

[0020] Figure 2 This is a schematic diagram of the i-th input switch circuit of this utility model.

[0021] Figure 3 This is a schematic diagram of the i-th input voltage sampling circuit and the i-th input current sampling circuit of this utility model.

[0022] Figure 4 This is a schematic diagram of the i-th power supply control circuit of this utility model.

[0023] Figure 5 This is a schematic diagram of the DC-DC converter control unit of this utility model. Detailed Implementation

[0024] To further explain the technical solution of this utility model, the following detailed description is provided through specific embodiments.

[0025] like Figures 1 to 5 As shown, this utility model discloses a multi-input DC-DC converter system, which includes N input control units, a DC-DC converter control unit, and an MCU module. The DC-DC converter control unit includes a DC-DC converter module, a total input voltage sampling circuit, and a total output voltage sampling circuit. The total input voltage sampling circuit is connected to the DC-DC converter module and is used to collect the input voltage of the DC-DC converter module. The total output voltage sampling circuit is connected to the DC-DC converter module and is used to collect the output voltage of the DC-DC converter module. The output terminals of the total input voltage sampling circuit and the total output voltage sampling circuit are connected to the MCU module. The DC-DC converter module is connected to the MCU module, and the MCU module can control the output voltage of the DC-DC converter module to adjust the output power of the DC-DC converter module. The N input control units are divided into the first input control unit to the Nth input control unit. The i-th input control unit includes the i-th input switch circuit and the i-th input voltage sampling circuit. The input terminal of the i-th input switch circuit is used to connect to the DC input voltage, and the output terminal of the i-th input switch circuit is connected to the input terminal of the DC-DC converter module. The control terminal of the i-th input switch circuit is connected to the MCU module. i is an integer from 1 to N.

[0026] In this invention, multiple input control units are used to receive different DC input voltages, and a single DC-DC converter control unit is used to perform DC-DC conversion. This results in a simpler structure and lower cost. Furthermore, the MCU module enables coordinated control of the various input control units and the DC-DC converter control unit, ensuring the normal operation of the entire multi-input DC-DC converter system.

[0027] To facilitate understanding of this utility model, the control method of the multi-input DC-DC converter system of this utility model is described in detail below, which includes the following sequential steps: Initialization steps: When the multi-input DC-DC converter system is powered on, the MCU module controls the i-th input switch circuit of the i-th input control unit to turn off (that is, when all i-th electronic switch circuits are turned off, the MCU module controls each input control unit not to supply power to the DC-DC converter module, ensuring the power-on safety of the entire multi-input DC-DC converter system). Automatic adjustment steps: Step S1: The MCU module obtains the input voltage of the j-th input switch circuit through the j-th input voltage sampling circuit and determines whether the input voltage of the j-th input switch circuit is normal. If the input voltage of the j-th input switch circuit is abnormal, the MCU module controls the j-th input switch circuit to remain off. If the input voltage of the j-th input switch circuit is normal, the MCU module controls the j-th input switch circuit to be turned on, so that the output voltage of the j-th input switch circuit is supplied to the DC-DC converter module, and performs one count. j takes values ​​from 1 to N in sequence, and when the count is 1, step S1 ends and step S2 is entered. Step S2: The MCU module obtains the input voltage of the k-th input switch circuit through the k-th input voltage sampling circuit and determines whether the input voltage of the k-th input switch circuit is normal (whether the input voltage is normal is determined by whether the input voltage is within the set threshold range); if the input voltage of the k-th input switch circuit is abnormal, the MCU module controls the k-th input switch circuit to remain off; if the input voltage of the k-th input switch circuit is normal, the MCU module obtains the input voltage of the DC-DC converter module through the total input voltage sampling circuit and determines whether the difference between the input voltage of the DC-DC converter module and the input voltage of the k-th input switch circuit exceeds [a certain threshold]. Set a threshold; if the threshold is not exceeded, the MCU module controls the k-th input switch circuit to turn on, so that the output voltage of the k-th input switch circuit is supplied to the DC-DC converter module; if the threshold is exceeded, the MCU module first adjusts the output power of the DC-DC converter module until the difference between the input voltage of the DC-DC converter module and the input voltage of the k-th input switch circuit does not exceed the threshold, and then the MCU module controls the k-th input switch circuit to turn on, so that the output voltage of the k-th input switch circuit is supplied to the DC-DC converter module; the value of k is cyclically taken from the i-th value corresponding to each i-th input switch circuit in the off state, that is, step S2 is performed cyclically; In addition, the control method also includes a timed self-test step performed synchronously with step S2: the MCU module periodically detects the m-th input switch circuit that is turned on, where m is the value of i of the i-th input switch circuit that is controlled to be turned on in the automatic adjustment step. The detection method is as follows: the MCU module first controls the m-th input switch circuit to turn off, and then the MCU module obtains the input voltage of the m-th input switch circuit through the input voltage sampling circuit and the input voltage of the DC-DC converter module through the total input voltage sampling circuit, and determines whether the input voltage of the m-th input switch circuit is normal and whether the difference between the input voltage of the DC-DC converter module and the input voltage of the m-th input switch circuit exceeds a set threshold. If the input voltage of the m-th input switch circuit is normal, the MCU module first controls the m-th input switch circuit to turn on; if the input voltage of the m-th input switch circuit is abnormal or the difference between the input voltage of the DC-DC converter module and the input voltage of the m-th input switch circuit exceeds the set threshold, the MCU module controls the m-th input switch circuit to remain off, and at the same time the MCU module adjusts the output power of the DC-DC converter module until the output power of the DC-DC converter module meets the set power range.

[0028] As described above, the control method of this invention can automatically adjust the output power of the DC-DC converter module (i.e., automatic adjustment step) when multiple normal DC input voltages are input, ensuring the constant output power of the DC-DC converter module, thereby protecting the downstream circuits (such as batteries or loads) connected to the DC-DC converter module. Furthermore, the control method of this invention can also perform periodic self-checks (i.e., periodic self-check step) to effectively detect input abnormalities and improve the reliability of the entire multi-input DC-DC converter system.

[0029] In an embodiment of this utility model, the i-th input control unit may further include an i-th power control circuit for providing a drive power supply VDD-i to the i-th input switch circuit. The control terminal of the i-th power control circuit is connected to the MCU module, and the MCU module controls whether the i-th power control circuit outputs the drive power supply VDD-i. When the MCU module controls the i-th input switch circuit to turn off, the MCU module also controls the i-th power control circuit not to output the drive power supply VDD-i, effectively reducing power consumption. When the MCU module controls the i-th input switch circuit to turn on, the MCU module also controls the i-th power control circuit to output the drive power supply VDD-i to ensure the conduction of the i-th input switch circuit.

[0030] In an embodiment of this utility model, the i-th input switch circuit includes an i-th optocoupler isolation circuit, an i-th amplifier circuit, and an i-th electronic switch circuit. The input terminal of the i-th optocoupler isolation circuit is connected to the control terminal of the i-th input switch circuit. The input terminal of the i-th optocoupler isolation circuit is connected to the input terminal of the i-th amplifier circuit. The output terminal of the i-th optocoupler isolation circuit is connected to the input terminal of the i-th amplifier circuit. The output terminal of the i-th amplifier circuit is connected to the control terminal of the i-th electronic switch circuit. The power supply terminal of the i-th amplifier circuit is used to connect to the driving power supply VDD-i. The input terminal and output terminal of the i-th electronic switch circuit are respectively connected to the input terminal and output terminal of the i-th input switch circuit. The i-th optocoupler isolation circuit provides isolation protection, the i-th amplifier circuit amplifies the signal and effectively drives the i-th electronic switch circuit, and the i-th electronic switch circuit controls the on / off state of the i-th input switch circuit. The i-th optocoupler isolation circuit may include resistors R11-i, R12-i, R13-i, R14-i, R15-i, transistor Q10-i, and optocoupler OC11-i. The first terminal of resistor R11-i is connected to the input terminal of the i-th optocoupler isolation circuit. The second terminal of resistor R11-i is connected to the first terminal of resistor R12-i and the base of transistor Q10-i. The second terminal of resistor R12-i and the emitter of transistor Q10-i are connected to a first ground. The collector of 10-i is connected to the negative terminal of the input side of optocoupler OC11-i. The positive terminal of the input side of optocoupler OC11-i is connected to the first terminal of resistor R13-i. The second terminal of resistor R13-i is connected to the control power supply VCC. The positive terminal of the output side of optocoupler OC11-i is connected to the drive power supply VDD-i through resistor R14-i. The negative terminal of the output side of optocoupler OC11-i and the first terminal of resistor R15-i are connected to the output terminal of the i-th optocoupler circuit. The second terminal of resistor R15-i is connected to the second ground. The i-th amplifier circuit may include resistors R16-i and R17-i, transistors Q11-i and Q12-i. The bases of transistors Q11-i and Q12-i are connected to the input terminal of the i-th amplifier circuit. The collector of transistor Q11-i is connected to the power supply terminal of the i-th amplifier circuit. The emitters of transistors Q11-i and Q12-i are connected to the first terminals of resistors R16-i and R17-i. The collector of transistor Q12-i and the second terminal of resistor R17-i are connected to a second ground. The second terminal of resistor R16-i is connected to the output terminal of the i-th amplifier circuit. The power supply terminal of the i-th amplifier circuit can be grounded through capacitor C11-i to improve the stability of the power supply voltage of the i-th amplifier circuit.The i-th electronic switch circuit includes MOSFETs M11-i and M12-i. The gates of MOSFETs M11-i and M12-i are connected to the control terminal of the i-th electronic switch circuit. The source of MOSFET M11-i is connected to the input terminal of the i-th electronic switch circuit. The drain of MOSFET M11-i is connected to the source of MOSFET M12-i. The drain of MOSFET M12-i is connected to the output terminal of the i-th electronic switch circuit. MOSFETs M11-i and M12-i are connected in series, causing their respective body diodes to be connected in reverse series, thus providing bidirectional isolation when MOSFETs M11-i and M12-i are turned off. Specifically, when the MCU module inputs a high-level signal to the control terminal of the i-th input switch circuit, MOSFETs M11-i and M12-i are turned on; and when the MCU module inputs a low-level signal to the control terminal of the i-th input switch circuit, MOSFETs M11-i and M12-i are turned off.

[0031] In an embodiment of this utility model, the i-th power supply control circuit may include resistors R41-i, R42-i, R43-i, R44-i, R45-i, capacitors C41-i and C42-i, Zener diodes D41-i and D42-i, transistors Q41-i, Q42-i, and Q43-i. The first terminal of resistor R41-i is connected to the control terminal of the i-th power supply control circuit. The second terminal of resistor R41-i and the first terminal of resistor R42-i are connected to the base of transistor Q41-i. The emitter of transistor Q41-i and the second terminal of resistor R42-i are connected to a first ground. The collector of transistor Q41-i and the first terminal of resistor R44-i are connected to the bases of transistors Q42-i and Q43-i. The second terminal of resistor R44-i is connected to resistor R43-i. The first terminal of resistor R43-i is connected to the collector of transistor Q42-i. The second terminal of resistor R43-i is connected to the control power supply VCC. The second terminal of resistor R43-i can be grounded through capacitor C43-i. The emitter of transistor Q42-i and the emitter of transistor Q43-i are connected to the first terminal of resistor R45-i. The collector of transistor Q43-i is connected to the first ground. The second terminal of resistor R45-i is connected to the first terminal of capacitor C41-i. The second terminal of capacitor C41-i is connected to the positive terminal of Zener diode D41-i and the negative terminal of Zener diode D42-i. The negative terminal of Zener diode D41-i and the first terminal of capacitor C42-i are connected to the output terminal of the i-th power supply control circuit. The output terminal of the i-th power supply control circuit is used to output the drive power supply VDD-i. The positive terminal of Zener diode D42-i and the second terminal of capacitor C42-i are connected to the input terminal of the i-th input switch circuit. When the MCU module inputs a PWM signal with a duty cycle of 50% to the control terminal of the i-th power control circuit, the i-th power control circuit outputs a rectified drive power supply VDD-i.

[0032] In an embodiment of this utility model, the i-th input voltage sampling circuit includes resistors R21-i and R22-i. The cooperation between resistors R21-i and R22-i has a voltage dividing effect. The first end of resistor R21-i is connected to the input terminal of the i-th input voltage sampling circuit, and the input terminal of the i-th input voltage sampling circuit is connected to the input terminal of the i-th input switch circuit. The second end of resistor R21-i and the first end of resistor R22-i are connected to the output terminal of the i-th input voltage sampling circuit, and the second end of resistor R22-i is connected to the first ground.

[0033] In an embodiment of this utility model, the i-th input control unit further includes an i-th input current sampling circuit. The i-th input current sampling circuit is connected to the i-th input switch circuit and is used to collect the input current of the i-th input switch circuit. The output terminal of the i-th input current sampling circuit is connected to the MCU module. The MCU module obtains the input current of the i-th input switch circuit through the i-th input current sampling circuit. When the input current of the i-th input switch circuit is abnormal, it controls the i-th input switch circuit to turn off to protect the entire system. The input terminal of the i-th input switch circuit is connected in series with a resistor R0-i. The i-th input current sampling circuit includes resistors R31-i, R32-i, R33-i, R34-i, R35-i, R36-i, and an operational amplifier OP31-i. The first terminal of resistor R31-i is connected to the first terminal of resistor R0-i. The second terminal of resistor R31-i and the first terminal of resistor R33-i are connected to the inverting input terminal of operational amplifier OP31-i. The first terminal of resistor R32-i is connected to the second terminal of resistor R0-i. The second terminal of resistor R32-i is connected to the second terminal of resistor R0-i. The first terminal of resistor R34-i is connected to the non-inverting input terminal of op-amp OP31-i. The first terminal of resistor R34-i is connected to the first ground. The second terminal of resistor R33-i and the first terminal of resistor R35-i are connected to the output terminal of op-amp OP31-i. The second terminal of resistor R35-i and the first terminal of resistor R36-i are connected to the output terminal of the i-th input current sampling circuit. The first terminal of resistor R36-i is connected to the first ground. The output terminal of the i-th input current sampling circuit can be grounded through capacitor C31-i to improve the stability of the output voltage of the i-th input current sampling circuit.

[0034] In an embodiment of this utility model, the total input voltage sampling circuit may include resistors R51-i and R52-i. The cooperation of resistors R51-i and R52-i has a voltage divider effect. The first end of resistor R51-i is connected to the input terminal of the total input voltage sampling circuit, which is connected to the input terminal of the DC-DC converter module. The second end of resistor R51-i and the first end of resistor R52-i are connected to the output terminal of the total input voltage sampling circuit, and the second end of resistor R52-i is connected to a first ground. The total output voltage sampling circuit may include resistor R... Resistor R61-i and resistor R62-i work together to divide the voltage. The first end of resistor R61-i is connected to the input of the total output voltage sampling circuit, which is connected to the output of the DC-DC converter module. The second end of resistor R61-i and the first end of resistor R62-i are connected to the output of the total output voltage sampling circuit, and the second end of resistor R62-i is connected to ground. The MCU module obtains the output voltage of the DC-DC converter module through the total output voltage sampling circuit to obtain the output power of the DC-DC converter module.

[0035] In the embodiments of this utility model, the MCU module can be a single-chip microcomputer U1; and the specific implementation method of the MCU module adjusting the output power of the DC-DC converter module is prior art, and will not be elaborated here.

[0036] The above embodiments and figures are not intended to limit the product form and style of this utility model. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of this utility model.

Claims

1. A multi-input DC-DC converter system, characterized in that: It includes N input control units, a DC-DC converter control unit, and an MCU module; The DC-DC converter control unit includes a DC-DC converter module, a total input voltage sampling circuit, and a total output voltage sampling circuit. The total input voltage sampling circuit is connected to the DC-DC converter module and is used to acquire the input voltage of the DC-DC converter module. The total output voltage sampling circuit is connected to the DC-DC converter module and is used to acquire the output voltage of the DC-DC converter module. The output terminals of the total input voltage sampling circuit and the total output voltage sampling circuit are connected to the MCU module. The DC-DC converter module is connected to the MCU module, and the MCU module can control the output voltage of the DC-DC converter module. The N input control units are divided into the first input control unit to the Nth input control unit; the i-th input control unit includes the i-th input switch circuit and the i-th input voltage sampling circuit; the input terminal of the i-th input switch circuit is used to connect to the DC input voltage, the output terminal of the i-th input switch circuit is connected to the input terminal of the DC-DC converter module, and the control terminal of the i-th input switch circuit is connected to the MCU module; the i-th input voltage sampling circuit is connected to the i-th input switch circuit and is used to collect the input voltage of the i-th input switch circuit, and the output terminal of the i-th input voltage sampling circuit is connected to the MCU module. i is an integer from 1 to N.

2. The multi-input DC-DC converter system as described in claim 1, characterized in that: The i-th input control unit also includes an i-th power supply control circuit for providing drive power VDD-i to the i-th input switch circuit. The control terminal of the i-th power supply control circuit is connected to the MCU module, and the MCU module controls whether the i-th power supply control circuit outputs drive power VDD-i.

3. The multi-input DC-DC converter system as described in claim 2, characterized in that: The i-th input switch circuit includes an i-th optocoupler isolation circuit, an i-th amplifier circuit, and an i-th electronic switch circuit. The input terminal of the i-th optocoupler isolation circuit is connected to the control terminal of the i-th input switch circuit. The input terminal of the i-th optocoupler isolation circuit is connected to the input terminal of the i-th amplifier circuit. The output terminal of the i-th optocoupler isolation circuit is connected to the input terminal of the i-th amplifier circuit. The output terminal of the i-th amplifier circuit is connected to the drive power supply VDD-i. The input terminal and output terminal of the i-th electronic switch circuit are respectively connected to the input terminal and output terminal of the i-th input switch circuit.

4. The multi-input DC-DC converter system as described in claim 3, characterized in that: The i-th optocoupler isolation circuit includes resistors R11-i, R12-i, R13-i, R14-i, R15-i, transistor Q10-i, and optocoupler OC11-i. The first terminal of resistor R11-i is connected to the input terminal of the i-th optocoupler isolation circuit. The second terminal of resistor R11-i is connected to the first terminal of resistor R12-i and the base of transistor Q10-i. The second terminal of resistor R12-i and the emitter of transistor Q10-i are connected to ground. The collector of 10-i is connected to the negative terminal of the input side of optocoupler OC11-i. The positive terminal of the input side of optocoupler OC11-i is connected to the first terminal of resistor R13-i. The second terminal of resistor R13-i is connected to the control power supply VCC. The positive terminal of the output side of optocoupler OC11-i is connected to the drive power supply VDD-i through resistor R14-i. The negative terminal of the output side of optocoupler OC11-i and the first terminal of resistor R15-i are connected to the output terminal of the i-th optocoupler circuit. The second terminal of resistor R15-i is connected to the second ground.

5. The multi-input DC-DC converter system as described in claim 3, characterized in that: The i-th amplifier circuit includes resistors R16-i and R17-i, transistors Q11-i and Q12-i. The bases of transistors Q11-i and Q12-i are connected to the input terminal of the i-th amplifier circuit. The collector of transistor Q11-i is connected to the power supply terminal of the i-th amplifier circuit. The emitters of transistors Q11-i and Q12-i are connected to the first terminals of resistors R16-i and R17-i. The collector of transistor Q12-i and the second terminal of resistor R17-i are connected to a second ground. The second terminal of resistor R16-i is connected to the output terminal of the i-th amplifier circuit.

6. The multi-input DC-DC converter system as described in claim 3, characterized in that: The i-th electronic switch circuit includes MOSFETs M11-i and M12-i. The gates of MOSFETs M11-i and M12-i are connected to the control terminal of the i-th electronic switch circuit. The source of MOSFET M11-i is connected to the input terminal of the i-th electronic switch circuit. The drain of MOSFET M11-i is connected to the source of MOSFET M12-i. The drain of MOSFET M12-i is connected to the output terminal of the i-th electronic switch circuit.

7. The multi-input DC-DC converter system as described in claim 2, characterized in that: The i-th power supply control circuit includes resistors R41-i, R42-i, R43-i, R44-i, R45-i, capacitors C41-i and C42-i, Zener diodes D41-i and D42-i, transistors Q41-i, Q42-i, and Q43-i. The first terminal of resistor R41-i is connected to the control terminal of the i-th power supply control circuit. The second terminal of resistor R41-i and the first terminal of resistor R42-i are connected to the base of transistor Q41-i. The emitter of transistor Q41-i and the second terminal of resistor R42-i are connected to ground. The collector of transistor Q41-i and the first terminal of resistor R44-i are connected to the bases of transistors Q42-i and Q43-i. The second terminal of resistor R44-i is connected to... The first terminal of resistor R43-i is connected to the collector of transistor Q42-i. The second terminal of resistor R43-i is connected to the control power supply VCC. The emitter of transistor Q42-i and the emitter of transistor Q43-i are connected to the first terminal of resistor R45-i. The collector of transistor Q43-i is connected to the first ground. The second terminal of resistor R45-i is connected to the first terminal of capacitor C41-i. The second terminal of capacitor C41-i is connected to the positive terminal of Zener diode D41-i and the negative terminal of Zener diode D42-i. The negative terminal of Zener diode D41-i and the first terminal of capacitor C42-i are connected to the output terminal of the i-th power supply control circuit. The output terminal of the i-th power supply control circuit is used to output the drive power supply VDD-i. The positive terminal of Zener diode D42-i and the second terminal of capacitor C42-i are connected to the input terminal of the i-th input switch circuit.

8. The multi-input DC-DC converter system as described in claim 1, characterized in that: The i-th input voltage sampling circuit includes resistors R21-i and R22-i. The first end of resistor R21-i is connected to the input terminal of the i-th input voltage sampling circuit, and the input terminal of the i-th input voltage sampling circuit is connected to the input terminal of the i-th input switch circuit. The second end of resistor R21-i and the first end of resistor R22-i are connected to the output terminal of the i-th input voltage sampling circuit, and the second end of resistor R22-i is connected to the first ground.

9. The multi-input DC-DC converter system as described in claim 1, characterized in that: The i-th input control unit also includes an i-th input current sampling circuit, which is connected to the i-th input switch circuit and used to collect the input current of the i-th input switch circuit. The output of the i-th input current sampling circuit is connected to the MCU module. The input terminal of the i-th input switch circuit is connected in series with a resistor R0-i; the i-th input current sampling circuit includes resistors R31-i, R32-i, R33-i, R34-i, R35-i, R36-i and operational amplifier OP31-i. The first terminal of resistor R31-i is connected to the first terminal of resistor R0-i, and the second terminal of resistor R31-i and the first terminal of resistor R33-i are connected to the inverting input terminal of operational amplifier OP31-i. The first terminal of resistor R32-i... The second terminal of resistor R0-i is connected to the first terminal of resistor R32-i. The second terminal of resistor R34-i and the first terminal of resistor R34-i are connected to the first ground. The second terminal of resistor R33-i and the first terminal of resistor R35-i are connected to the output terminal of op-amp OP31-i. The second terminal of resistor R35-i and the first terminal of resistor R36-i are connected to the output terminal of the i-th input current sampling circuit. The first terminal of resistor R36-i is connected to the first ground.

10. The multi-input DC-DC converter system as described in claim 1, characterized in that: The total input voltage sampling circuit includes resistors R51-i and R52-i. The first end of resistor R51-i is connected to the input terminal of the total input voltage sampling circuit, and the input terminal of the total input voltage sampling circuit is connected to the input terminal of the DC-DC converter module. The second end of resistor R51-i and the first end of resistor R52-i are connected to the output terminal of the total input voltage sampling circuit, and the second end of resistor R52-i is connected to the first ground. The total output voltage sampling circuit includes resistors R61-i and R62-i. The first end of resistor R61-i is connected to the input terminal of the total output voltage sampling circuit, and the input terminal of the total output voltage sampling circuit is connected to the output terminal of the DC-DC converter module. The second end of resistor R61-i and the first end of resistor R62-i are connected to the output terminal of the total output voltage sampling circuit, and the second end of resistor R62-i is connected to the first ground.

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