DCDC power conversion device

Abstract

A DCDC power conversion device comprises a first-stage voltage input module, a switch module, a first-stage DCDC conversion module, a second-stage voltage input module, a second-stage DCDC conversion module, a control module and a bypass module which are connected in sequence. The control module is connected with a first end of the first-stage voltage input module to receive a first-stage input voltage, and generates a control signal for controlling the bypass module to be conducted based on the first-stage input voltage and an output set voltage; and the bypass module is connected between the first end of the first-stage voltage input module and the first end of the second-stage voltage input module, and is conducted based on the control signal to bypass the first-stage DCDC conversion module. By designing the bypass module controlled to be conducted, when two-stage DCDC conversion is not needed, the first DCDC conversion module is bypassed, and by means of the ingenious design, on the premise that normal work of the circuit is not affected, circuit loss is reduced, and circuit efficiency is improved.

Description

Technical Field

[0001] The utility model relates to a power supply module, and more specifically to a DCDC power conversion device. Background Art

[0002] Against the backdrop of the country's vigorous promotion of carbon neutrality, the application of photovoltaic storage and charging scenarios has emerged. In some photovoltaic storage and charging scenarios, energy storage battery packs are generally configured. The energy storage battery pack can charge the battery on the electric vehicle through a power conversion device. Current power conversion devices usually include a two-stage DCDC circuit, in which the input voltage range of the first-stage DCDC circuit is usually wider, and the input voltage is converted by the first-stage DCDC circuit and used as the input voltage of the second-stage DCDC circuit. In the prior art, the input voltage needs to be converted in two stages through the first-stage DCDC circuit and the second-stage DCDC circuit in sequence before being output. The two-stage DCDC conversion is bound to cause losses, resulting in low circuit efficiency. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a DCDC power conversion device in view of the above-mentioned defects of the prior art, which can reduce circuit loss and improve circuit efficiency by adopting a very simple circuit through clever design.

[0004] The technical solution adopted by the utility model to solve the technical problem is: construct a DCDC power conversion device, including a first-stage voltage input module, a switch module, a first-stage DCDC conversion module, a second-stage voltage input module and a second-stage DCDC conversion module connected in sequence, characterized in that it further includes a control module and a bypass module;

[0005] The control module is connected to the first end of the first-stage voltage input module to receive the first-stage input voltage, and generates a control signal for controlling the conduction of the bypass module based on the first-stage input voltage and the output setting voltage;

[0006] The bypass module is connected between the first end of the first-stage voltage input module and the first end of the second-stage voltage input module, and is turned on based on the control signal to bypass the first-stage DCDC conversion module.

[0007] In the DCDC power conversion device described in the utility model, the bypass module includes a normally open switch device, a first end of the normally open switch device is connected to the first end of the first-level voltage input module, and a second end is connected to the first end of the second-level voltage input module. The normally open switch device is turned on based on the control signal to directly connect the first end of the first-level voltage input module with the first end of the second-level voltage input module to bypass the first-level DCDC conversion module.

[0008] In the DCDC power conversion device described in the utility model, the second-level voltage input module includes a first capacitor and a second capacitor, the first capacitor and the second capacitor are connected in series between the first end and the second end of the second-level voltage input module, the first end of the second-level voltage input module is simultaneously connected to the first output end of the first-level DCDC conversion module and the first input end of the second-level DCDC conversion module, and the second end of the second-level voltage input module is simultaneously connected to the second output end of the first-level DCDC conversion module, the second input end of the second-level DCDC conversion module and the ground.

[0009] In the DCDC power conversion device described in the utility model, the switch module includes a first switch and a first resistor, the first end of the first switch is connected to the first end of the first-level voltage input module, and the second end is connected to the first input end of the first-level DCDC conversion module, the first end of the first resistor is connected to the first end of the first-level voltage input module, and the second end is connected to the first input end of the first-level DCDC conversion module.

[0010] In the DCDC power conversion device described in the utility model, the switch module further includes a first diode, an anode of the first diode is connected to the second end of the first resistor, and a cathode of the first diode is connected to the first input end of the first-stage DCDC conversion module.

[0011] In the DCDC power conversion device described in the utility model, the first-stage DCDC conversion module includes a first switch tube, a second switch tube, an inductor, a second diode and a third diode;

[0012] The control ends of the first switch tube and the second switch tube receive control signals respectively, the first end of the first switch tube is connected to the second end of the second switch tube and the midpoint of the first capacitor and the second capacitor, the second end of the first switch tube is connected to the anode of the second diode and the first end of the inductor, the second end of the inductor is the first input end of the first-stage DCDC conversion module, the cathode of the second diode is the first output end of the first-stage DCDC conversion module, the first end of the second switch tube is connected to the cathode of the third diode and ground, and the anode of the third diode is the second end of the second-stage voltage input module.

[0013] In the DCDC power conversion device described in the utility model, the first-stage DCDC conversion module includes a first switch tube, a second switch tube, a common-mode inductor, a second diode and a third diode;

[0014] The control ends of the first switch tube and the second switch tube receive control signals respectively, the first end of the first switch tube is connected to the second end of the second switch tube and the midpoint of the first capacitor and the second capacitor, the second end of the first switch tube is connected to the anode of the second diode and the first end of the common-mode inductor, the cathode of the second diode is the first output end of the first-stage DCDC conversion module, the first end of the second switch tube is connected to the cathode of the third diode and the second end of the common-mode inductor, the anode of the third diode is the second end of the second-stage voltage input module, the third end of the common-mode inductor is the first input end of the first-stage DCDC conversion module, and the fourth end of the common-mode inductor is the second input end of the first-stage DCDC conversion module and is grounded.

[0015] The DCDC power conversion device of the utility model is implemented by designing a controlled conduction bypass module, and bypassing the first DCDC conversion module when there is no need to perform two-stage DCDC conversion. Therefore, through ingenious design, a very simple circuit can be used to reduce circuit loss and improve circuit efficiency without affecting the normal operation of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0017] Figure 1 It is a principle block diagram of a preferred embodiment of the DCDC power conversion device of the utility model;

[0018] Figure 2 It is a circuit diagram of another preferred embodiment of the DCDC power conversion device of the utility model;

[0019] Figure 3 It is a circuit diagram of another preferred embodiment of the DCDC power conversion device of the utility model;

[0020] Figure 4 This is a circuit diagram of another preferred embodiment of the DCDC power conversion device of the utility model. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0022] Figure 1 1 is a principle block diagram of a preferred embodiment of the DCDC power conversion device of the present utility model. Figure 1As shown, the DCDC power conversion device includes a first-stage voltage input module 100, a switch module 200, a first-stage DCDC conversion module 300, a second-stage voltage input module 400 and a second-stage DCDC conversion module 500, a control module 600 and a bypass module 700 connected in sequence.

[0023] In the present invention, the first-stage voltage input module 100, the switch module 200, the first-stage DCDC conversion module 300, the second-stage voltage input module 400 and the second-stage DCDC conversion module 500 can adopt any design and connection known in the prior art, as long as they can complete the secondary DCDC power conversion.

[0024] The control module 600 is connected to the first end of the first-stage voltage input module 100 to receive the first-stage input voltage, and generates a control signal to control the bypass module 700 to be turned on based on the first-stage input voltage and the output setting voltage. The bypass module 700 is connected between the first end of the first-stage voltage input module 100 and the first end of the second-stage voltage input module 400, and is turned on based on the control signal to bypass the first-stage DCDC conversion module 300. In a preferred embodiment of the utility model, the control module 600 can be a DSP controller, and the bypass module 700 can use any known switch device, such as a relay, a switch tube, etc. The bypass module 700 is preferably a normally open switch device, which is only turned on when receiving a control signal.

[0025] Those skilled in the art know that the range of the first-level input voltage of the first-level voltage input module 100 is usually wide. After the first-level input voltage Vi+ and Vi- are converted by the first-level DCDC conversion module 300, they are used as the input voltage Co+ and Co- of the second-level DCDC conversion module 500, and are output to the load for use after conversion by the second-level DCDC conversion module 500. After the power supply is powered on, the control module 600 can know the required voltage of the second-level DCDC conversion module 500 by outputting the set voltage Vo+ and Vo-, that is, the required voltage Co+ and Co- at both ends of the second-level voltage input module 400. If at this time, the first-level input voltage Vi+ and Vi- do not meet the voltage required by the second-level DCDC conversion module 500, then it is necessary to convert it through the first-level DCDC conversion module 300. If at this time, the first-level input voltage Vi+ and Vi- actually meet the voltage required by the second-level DCDC conversion module 500, then the conversion of the first-level DCDC conversion module 300 is actually unnecessary. Moreover, this unnecessary process also causes loss, thus resulting in low circuit efficiency.

[0026] Based on this, the control module 600 is connected to the first end of the first-stage voltage input module 100 to receive the first-stage input voltage, and generates a control signal for controlling the conduction of the bypass module 700 based on the first-stage input voltage and the output setting voltage. That is, when the first-stage input voltage meets (i.e., is greater than or equal to) the output setting voltage, the first-stage DCDC conversion module 300 is directly bypassed (i.e., short-circuited) through the bypass module 700, thereby avoiding the loss caused by the first-stage conversion and improving the circuit efficiency.

[0027] The DCDC power conversion device of the utility model is implemented by designing a controlled conduction bypass module, and bypassing the first DCDC conversion module when there is no need to perform two-stage DCDC conversion. Therefore, through ingenious design, a very simple circuit can be used to reduce circuit loss and improve circuit efficiency without affecting the normal operation of the circuit.

[0028] Figure 2 This is a circuit diagram of another preferred embodiment of the DCDC power conversion device of the utility model. For the sake of simplicity, the control module is not shown. The control module can preferably adopt a DSP controller. Figure 1 The DCDC power conversion device includes a first-stage voltage input module 100, a switch module 200, a first-stage DCDC conversion module 300, a second-stage voltage input module 400, and a second-stage DCDC conversion module 500, a control module 600, and a bypass module 700, which are connected in sequence. The control module 600 is connected to the first end of the first-stage voltage input module 100 to receive the first-stage input voltage, and generates a control signal for controlling the bypass module 700 to be turned on based on the first-stage input voltage and the output setting voltage. The bypass module 700 is connected between the first end of the first-stage voltage input module 100 and the first end of the second-stage voltage input module 400, and is turned on based on the control signal to bypass the first-stage DCDC conversion module 300.

[0029] Further Figure 2 As shown, the first-level voltage input module 100 is a power supply U1, which can also be one or more capacitors providing input voltage. The switch module 200 includes a first switch K1 and a resistor R1. The first-level DCDC conversion module 300 includes a switch tube Q1, a switch tube Q2, an inductor L1, a diode D1 and a diode D2. The second-level voltage input module 400 includes a capacitor C1 and a capacitor C2. The second-level DCDC conversion module 500 can adopt any known DCDC conversion module, circuit or chip according to actual needs. The control module 600 can preferably adopt a DSP controller. The bypass module 700 includes a normally open switch device K2.

[0030] like Figure 2As shown, the first end of the first switch K1 is connected to the first end of the power supply U1, and the second end is connected to the first input end of the first-stage DCDC conversion module 300, the first end of the resistor R1 is connected to the first end of the power supply U1, and the second end is connected to the first input end of the first-stage DCDC conversion module 300, and the second end of the power supply U1 is grounded.

[0031] The control ends of the switch tube Q1 and the switch tube Q2 receive control signals respectively, and the first end of the switch tube Q1 is connected to the second end of the switch tube Q2 and the midpoint of the capacitor C1 and the capacitor C2. The second end of the switch tube Q1 is connected to the anode of the diode D1 and the first end of the inductor L1, and the second end of the inductor L1 is the first input end of the first-stage DCDC conversion module 300. The cathode of the diode D1 is the first output end of the first-stage DCDC conversion module 300. The first end of the switch tube Q2 is connected to the cathode of the diode D2 and the ground, and the anode of the diode D2 is the second output end of the first-stage DCDC conversion module 300, which is connected to the second end of the second-stage voltage input module 400. The capacitor C1 and the capacitor C2 are connected in series between the first end and the second end of the second-stage voltage input module 400. The first end of the second-level voltage input module 400 is simultaneously connected to the first output end of the first-level DCDC conversion module 300 and the first input end of the second-level DCDC conversion module 500, and the second end of the second-level voltage input module 400 is simultaneously connected to the second output end of the first-level DCDC conversion module 300, the second input end of the second-level DCDC conversion module 500 and ground.

[0032] The first end of the normally-open switch device K2 is connected to the first end of the power supply U1, and the second end is connected to the first end of the second-stage voltage input module 400 (i.e., the first end of the capacitor C1). The normally-open switch device K2 is turned on based on the control signal to directly connect the first end of the power supply U1 with the first end of the second-stage voltage input module 400 to bypass the first-stage DCDC conversion module 300.

[0033] Combine the following Figure 2 The principle of the DCDC power conversion device of the present invention is further described as follows.

[0034] After the power supply is powered on, the control module 600 can know the voltage required by the second-level DCDC conversion module 500, that is, the voltage Co+ and Co- required at both ends of the capacitors C1 and C2, by outputting the set voltages Vo+ and Vo-. If the voltage across the power supply U1 is greater than the voltage Co+ and Co- required at both ends of the capacitors C1 and C2, the normally open switch device K2 (preferably a relay) is energized, and the power supply U1 directly supplies the second-level DCDC conversion module 500, and the inductor L1, diodes D1 and D2 are short-circuited and do not participate in the work, thereby reducing circuit losses and improving circuit efficiency. When the voltage across the power supply U1 is less than the voltage Co+ and Co- required at both ends of the capacitors C1 and C2, the normally open switch device K2 remains disconnected, which does not affect the normal operation of the circuit.

[0035] The DCDC power conversion device of the utility model is implemented by designing a controlled conduction bypass module, and bypassing the first DCDC conversion module when two-stage DCDC conversion is not required, so that the circuit loss can be reduced and the circuit efficiency can be improved without affecting the normal operation of the circuit through a clever design and a very simple circuit. And the first DCDC conversion module with a specific structure can simply and efficiently complete the first-stage DCDC voltage conversion.

[0036] Figure 3 This is a circuit diagram of another preferred embodiment of the DCDC power conversion device of the utility model. Figure 3 The embodiment shown and Figure 2 The embodiment shown is similar, except that it further includes an anti-reverse diode D3, the anode of the anti-reverse diode D3 is connected to the second end of the resistor R1, and the cathode is connected to the first input end of the first-stage DCDC conversion module 300 (ie, the second end of the inductor L1). Figure 3 The working principle of the embodiment shown is similar to Figure 2 The embodiments shown are similar and will not be described again here.

[0037] Figure 4 This is a circuit diagram of another preferred embodiment of the DCDC power conversion device of the utility model. Figure 4 The embodiment shown and Figure 3 The embodiment shown is similar to the embodiment shown in the figure, except that a common mode inductor is used instead of an inductor. Figure 4As shown, the second end of the switch tube Q1 is connected to the anode of the diode D1 and the first end of the common-mode inductor L1, the cathode of the diode D1 is the first output end of the first-stage DCDC conversion module 300, the first end of the switch tube Q2 is connected to the cathode of the diode D2 and the second end of the common-mode inductor L1, the anode of the diode D2 is the second output end of the first-stage DCDC conversion module 300, and it is connected to the second end of the second-stage voltage input module 400. The third end of the common-mode inductor L1 is the first input end of the first-stage DCDC conversion module 300, and the fourth end of the common-mode inductor L1 is the second input end of the first-stage DCDC conversion module 300 and is grounded. Figure 3 The working principle of the embodiment shown is similar to Figure 2 The embodiments shown are similar and will not be described again here.

[0038] The DCDC power conversion device of the utility model is implemented by designing a controlled conduction bypass module, and bypassing the first DCDC conversion module when two-stage DCDC conversion is not required, so that the circuit loss can be reduced and the circuit efficiency can be improved without affecting the normal operation of the circuit through a clever design and a very simple circuit. And the first DCDC conversion module with a specific structure can simply and efficiently complete the first-stage DCDC voltage conversion.

[0039] Although the present invention is described through specific embodiments, it should be understood by those skilled in the art that various changes and equivalent substitutions may be made to the present invention without departing from the scope of the present invention. In addition, various modifications may be made to the present invention for specific situations or materials without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed, but should include all implementation methods that fall within the scope of the claims of the present invention.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A DCDC power conversion device, comprising a first-stage voltage input module, a switch module, a first-stage DCDC conversion module, a second-stage voltage input module and a second-stage DCDC conversion module connected in sequence, characterized in that: further comprising a control module and a bypass module; The control module is connected to the first end of the first-stage voltage input module to receive the first-stage input voltage, and generates a control signal for controlling the conduction of the bypass module based on the first-stage input voltage and the output setting voltage; The bypass module is connected between the first end of the first-stage voltage input module and the first end of the second-stage voltage input module, and is turned on based on the control signal to bypass the first-stage DCDC conversion module.

2. The DCDC power conversion device according to claim 1, characterized in that: The bypass module includes a normally open switch device, a first end of the normally open switch device is connected to the first end of the first-level voltage input module, and a second end is connected to the first end of the second-level voltage input module. The normally open switch device is turned on based on the control signal to directly connect the first end of the first-level voltage input module with the first end of the second-level voltage input module to bypass the first-level DCDC conversion module.

3. The DCDC power conversion device according to claim 2, characterized in that: The second-level voltage input module includes a first capacitor and a second capacitor, the first capacitor and the second capacitor are connected in series between a first end and a second end of the second-level voltage input module, the first end of the second-level voltage input module is simultaneously connected to a first output end of the first-level DCDC conversion module and a first input end of the second-level DCDC conversion module, and the second end of the second-level voltage input module is simultaneously connected to a second output end of the first-level DCDC conversion module, a second input end of the second-level DCDC conversion module and ground.

4. The DCDC power conversion device according to claim 3, characterized in that: The switch module includes a first switch and a first resistor, wherein the first end of the first switch is connected to the first end of the first-stage voltage input module, and the second end is connected to the first input end of the first-stage DCDC conversion module; the first end of the first resistor is connected to the first end of the first-stage voltage input module, and the second end is connected to the first input end of the first-stage DCDC conversion module.

5. The DCDC power conversion device according to claim 4, characterized in that: The switch module further includes a first diode, an anode of the first diode is connected to the second end of the first resistor, and a cathode of the first diode is connected to the first input end of the first-stage DCDC conversion module.

6. The DCDC power conversion device according to any one of claims 3 to 5, characterized in that: The first-stage DCDC conversion module includes a first switch tube, a second switch tube, an inductor, a second diode and a third diode; The control ends of the first switch tube and the second switch tube receive control signals respectively, the first end of the first switch tube is connected to the second end of the second switch tube and the midpoint of the first capacitor and the second capacitor, the second end of the first switch tube is connected to the anode of the second diode and the first end of the inductor, the second end of the inductor is the first input end of the first-stage DCDC conversion module, the cathode of the second diode is the first output end of the first-stage DCDC conversion module, the first end of the second switch tube is connected to the cathode of the third diode and ground, and the anode of the third diode is the second end of the second-stage voltage input module.

7. The DCDC power conversion device according to any one of claims 3 to 5, characterized in that: The first-stage DCDC conversion module includes a first switch tube, a second switch tube, a common-mode inductor, a second diode and a third diode; The control ends of the first switch tube and the second switch tube receive control signals respectively, the first end of the first switch tube is connected to the second end of the second switch tube and the midpoint of the first capacitor and the second capacitor, the second end of the first switch tube is connected to the anode of the second diode and the first end of the common-mode inductor, the cathode of the second diode is the first output end of the first-stage DCDC conversion module, the first end of the second switch tube is connected to the cathode of the third diode and the second end of the common-mode inductor, the anode of the third diode is the second end of the second-stage voltage input module, the third end of the common-mode inductor is the first input end of the first-stage DCDC conversion module, and the fourth end of the common-mode inductor is the second input end of the first-stage DCDC conversion module and is grounded.

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