Voltage boosting type non-isolated DC-DC conversion circuit and construction method thereof

Abstract

The invention discloses a voltage boosting type non-isolated DC-DC conversion circuit and a construction method thereof. The voltage boosting type non-isolated DC-DC converter comprises a basic boosting type DC-DC converter and an auxiliary boosting module, the first end of the auxiliary boosting module is electrically connected with the first pre-stage output end, the second end is electrically connected with the pulse output end, and the third end is electrically connected with the second pre-stage output end; the auxiliary boosting module is used for boosting the voltage between the second end and the first end of the basic boosting type DC-DC converter or between the second end and the third end of the basic boosting type DC-DC converter in the charging stage of the basic boosting type DC-DC converter; and in the discharge stage, the output voltage of the basic boost DC-DC converter is transmitted to the other one between the second end and the first end or between the second end and the third end of the basic boost DC-DC converter. According to the invention, the boost capability can be improved on the premise of not increasing the cost and control complexity of the conversion circuit.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and particularly relates to a voltage-boosting non-isolated DC-DC conversion circuit and a method for constructing the same. Background Art

[0002] DC-DC converters are widely used in various step-down / step-up applications, such as in fuel cell systems, portable devices such as laptops and mobile phones, light-emitting diode products, automotive electronic devices, and so on. In some application scenarios, the input voltage level requirement of the electrical equipment is much higher than the voltage of the power supply, which requires the DC-DC converter to have a high boosting ability.

[0003] However, for the DC-DC converters in the related art, if they need to meet a high boosting ability, multiple controlled switching elements or isolation converters are required, which increases the design cost, volume, and control complexity of the converter. Summary of the Invention

[0004] The present invention provides a voltage-boosting non-isolated DC-DC conversion circuit and a method for constructing the same, so as to improve the boosting ability without increasing the cost and control complexity of the conversion circuit.

[0005] According to an aspect of the present invention, there is provided a voltage-boosting non-isolated DC-DC converter, comprising: a basic boost-type DC-DC converter and an auxiliary boost module;

[0006] The basic boost-type DC-DC converter includes a first pre-stage output terminal, a second pre-stage output terminal, a first inductor and a first diode connected in series between the first pre-stage output terminal and the second pre-stage output terminal, wherein a first end of the first inductor and a first end of the first diode are connected in series to a pulsating output terminal;

[0007] A first end of the auxiliary boost module is electrically connected to the first pre-stage output terminal, a second end of the auxiliary boost module is electrically connected to the pulsating output terminal, and a third end of the auxiliary boost module is electrically connected to the second pre-stage output terminal;

[0008] The auxiliary boost module is configured to boost the voltage between one of its second end and its first end, and between its second end and its third end during the charging stage of the basic boost-type DC-DC converter; and transfer the output voltage of the basic boost-type DC-DC converter to the other one between its second end and its first end, and between its second end and its third end during the discharging stage of the basic boost-type DC-DC converter.

[0009] Optionally, the auxiliary boost module includes a second diode, a first capacitor, a second capacitor, and a second inductor; the anode of the second diode is electrically connected to the first end of the auxiliary boost module, the cathode of the second diode is electrically connected to the first end of the first capacitor, the second end of the first capacitor is electrically connected to the second end of the auxiliary boost module, the first end of the second capacitor is electrically connected to the second end of the auxiliary boost module, the second end of the second capacitor is electrically connected to the first end of the second inductor, and the second end of the second inductor is electrically connected to the third end of the auxiliary boost module;

[0010] The auxiliary boost module is used to boost the voltage between its second end and its first end during the charging stage of the basic boost DC-DC converter; and transfer the output voltage of the basic boost DC-DC converter to between its second end and its third end during the discharging stage of the basic boost DC-DC converter.

[0011] Optionally, the auxiliary boost module includes a second diode, a first capacitor, a second capacitor, and a second inductor; the first end of the second inductor is electrically connected to the first end of the auxiliary boost module, the second end of the second inductor is electrically connected to the first end of the first capacitor, the second end of the first capacitor is electrically connected to the second end of the auxiliary boost module, the first end of the second capacitor is electrically connected to the second end of the auxiliary boost module, the second end of the second capacitor is electrically connected to the anode of the second diode, and the cathode of the second diode is electrically connected to the third end of the auxiliary boost module;

[0012] The auxiliary boost module is used to boost the voltage between its second end and its third end during the charging stage of the basic boost DC-DC converter; and transfer the output voltage of the basic boost DC-DC converter to between its second end and its first end during the discharging stage of the basic boost DC-DC converter.

[0013] Optionally, the basic boost DC-DC converter further includes a switching tube and a third capacitor; the second end of the first inductor serves as the first power input terminal of the basic boost DC-DC converter; the first end of the switching tube is electrically connected to the pulsating output terminal, the second end of the switching tube serves as the second power input terminal of the basic boost DC-DC converter, and the control terminal of the switching tube is connected to a control signal; the first end of the third capacitor is electrically connected to the second end of the first diode and the first pre-stage output terminal, and the second end of the third capacitor is electrically connected to the second end of the switching tube and the second pre-stage output terminal.

[0014] Optionally, the basic boost DC-DC converter further includes a switching transistor and a third capacitor; a first end of the switching transistor serves as a first power input terminal of the basic boost DC-DC converter, a second end of the switching transistor is electrically connected to the pulsating output terminal, and a control terminal of the switching transistor receives a control signal; a second end of the first inductor serves as a second power input terminal of the basic boost DC-DC converter; a first end of the third capacitor is electrically connected to a second end of the first diode and the second pre-stage output terminal, and a second end of the third capacitor is electrically connected to the second end of the first inductor and the first pre-stage output terminal.

[0015] Optionally, the basic boost DC-DC converter further includes a switching transistor, a third capacitor, a third inductor, and a fourth capacitor; a first end of the third inductor serves as a first power input terminal of the basic boost DC-DC converter, a second end of the third inductor is electrically connected to a first end of the fourth capacitor, and a second end of the fourth capacitor is electrically connected to the pulsating output terminal; a first end of the switching transistor is electrically connected to the second end of the third inductor, a second end of the switching transistor serves as a second power input terminal of the basic boost DC-DC converter, and a control terminal of the switching transistor receives a control signal; a second end of the first inductor is electrically connected to the second power input terminal; a first end of the third capacitor is electrically connected to a second end of the first diode and the first pre-stage output terminal, and a second end of the third capacitor is electrically connected to the second end of the switching transistor and the second pre-stage output terminal.

[0016] Optionally, the basic boost DC-DC converter further includes a switching transistor, a third capacitor, a third inductor, and a fourth capacitor; a first end of the switching transistor serves as a first power input terminal of the basic boost DC-DC converter, a second end of the switching transistor is electrically connected to a first end of the fourth capacitor, a control terminal of the switching transistor receives a control signal, and a second end of the fourth capacitor is electrically connected to the pulsating output terminal; a first end of the third inductor is electrically connected to the first end of the fourth capacitor, and a second end of the third inductor serves as a second power input terminal of the basic boost DC-DC converter; a second end of the first diode is electrically connected to the second pre-stage output terminal; a first end of the third capacitor is electrically connected to a second end of the first inductor and the first pre-stage output terminal, and a second end of the third capacitor is electrically connected to the second end of the first diode and the second pre-stage output terminal.

[0017] Optionally, the basic boost DC-DC converter further includes a switching transistor, a third capacitor, a third inductor, and a fourth capacitor; the first end of the third inductor serves as the first power input terminal of the basic boost DC-DC converter, the second end of the third inductor is electrically connected to the first end of the fourth capacitor, and the second end of the fourth capacitor is electrically connected to the second pre-stage output terminal; the first end of the switching transistor is electrically connected to the pulsating output terminal, the second end of the switching transistor is electrically connected to the second end of the third inductor, and the control terminal of the switching transistor receives a control signal; the second end of the first inductor serves as the second power input terminal of the basic boost DC-DC converter;

[0018] The second end of the first diode is electrically connected to the second pre-stage output terminal; the first end of the third capacitor is electrically connected to the second pre-stage output terminal, and the second end of the third capacitor is electrically connected to the second end of the first inductor and the first pre-stage output terminal.

[0019] According to another aspect of the present invention, there is provided a method for constructing a voltage-boosting non-isolated DC-DC conversion circuit, including:

[0020] Obtain the first pre-stage output terminal, the second pre-stage output terminal, and the pulsating output terminal of the basic boost DC-DC converter; wherein, the basic boost DC-DC converter includes a first inductor and a first diode connected in series between the first pre-stage output terminal and the second pre-stage output terminal, and the first end of the first inductor and the first end of the first diode are connected to the pulsating output terminal;

[0021] Connect the first end of the auxiliary boost module to the first pre-stage output terminal, connect the second end of the auxiliary boost module to the pulsating output terminal, and connect the third end of the auxiliary boost module to the second pre-stage output terminal; wherein, the auxiliary boost module is used to boost the voltage between its second end and its first end, and between its second end and its third end during the charging stage of the basic boost DC-DC converter; and transfer the output voltage of the basic boost DC-DC converter to the other one between its second end and its first end, and between its second end and its third end during the discharging stage of the basic boost DC-DC converter.

[0022] Optionally, the auxiliary boost module includes a second diode, a first capacitor, a second capacitor, and a second inductor; an anode of the second diode is electrically connected to a first end of the auxiliary boost module, a cathode of the second diode is electrically connected to a first end of the first capacitor, a second end of the first capacitor is electrically connected to a second end of the auxiliary boost module, a first end of the second capacitor is electrically connected to the second end of the auxiliary boost module, a second end of the second capacitor is electrically connected to a first end of the second inductor, and a second end of the second inductor is electrically connected to a third end of the auxiliary boost module;

[0023] Alternatively, the auxiliary boost module includes a second diode, a first capacitor, a second capacitor, and a second inductor; a first end of the second inductor is electrically connected to a first end of the auxiliary boost module, a second end of the second inductor is electrically connected to a first end of the first capacitor, a second end of the first capacitor is electrically connected to a second end of the auxiliary boost module, a first end of the second capacitor is electrically connected to the second end of the auxiliary boost module, a second end of the second capacitor is electrically connected to an anode of the second diode, and a cathode of the second diode is electrically connected to a third end of the auxiliary boost module.

[0024] The technical solution of the embodiment of the present invention, by setting an auxiliary boost module and using the output voltage of the basic boost-type DC-DC converter and the internal node as the boost source of the auxiliary boost module, can not only increase the boost ability but also does not require an additional switching tube, so that the boost ability can be improved without increasing the control difficulty, cost, and volume.

[0025] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.

[0027] Figure 1 FIG. is a schematic circuit diagram of a voltage-boosting non-isolated DC-DC conversion circuit provided in Embodiment 1 of the present invention;

[0028] Figure 2 FIG. is a schematic circuit diagram of an auxiliary boost module provided in Embodiment 2 of the present invention;

[0029] Figure 3Schematic diagram of a circuit structure of an auxiliary boost module provided in Embodiment 3 of the present invention;

[0030] Figure 4 Schematic diagram of a circuit structure after a voltage-boosting non-isolated DC-DC conversion circuit provided in Embodiment 4 of the present invention is connected to a load and a power supply;

[0031] Figure 5 For Figure 4 State diagram in the first mode;

[0032] Figure 6 For Figure 4 State diagram in the second mode;

[0033] Figure 7 Schematic diagram of a circuit structure of a voltage-boosting non-isolated DC-DC conversion circuit provided in Embodiment 5 of the present invention;

[0034] Figure 8 Schematic diagram of a circuit structure of a voltage-boosting non-isolated DC-DC conversion circuit provided in Embodiment 6 of the present invention;

[0035] Figure 9 Schematic diagram of a circuit structure of a voltage-boosting non-isolated DC-DC conversion circuit provided in Embodiment 7 of the present invention;

[0036] Figure 10 Schematic diagram of a circuit structure of a voltage-boosting non-isolated DC-DC conversion circuit provided in Embodiment 8 of the present invention;

[0037] Figure 11 Flow chart of a construction method of a voltage-boosting non-isolated DC-DC conversion circuit provided in Embodiment 9 of the present invention;

[0038] Figure 12 For Figure 4 An experimental waveform diagram of the shown circuit;

[0039] Figure 13 For Figure 4 Another experimental waveform diagram of the shown circuit. Detailed implementation manners

[0040] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0041] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present invention are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0042] Embodiment 1

[0043] Figure 1 FIG. is a schematic circuit diagram of a voltage-boosting non-isolated DC-DC conversion circuit provided in Embodiment 1 of the present invention. Refer to Figure 1 . The voltage-boosting non-isolated DC-DC conversion circuit includes: a basic boost-type DC-DC converter 11 and an auxiliary boost module 12; the basic boost-type DC-DC converter includes a first pre-stage output terminal Net_A, a second pre-stage output terminal Net_B, a first inductor L1 and a first diode D1 connected in series between the first pre-stage output terminal Net_A and the second pre-stage output terminal Net_B. Among them, the first end of the first inductor L1 and the first end of the first diode D1 are connected in series to the pulsating output terminal Net_C; the first end Net_a of the auxiliary boost module 12 is electrically connected to the first pre-stage output terminal Net_A, the second end Net_c of the auxiliary boost module 12 is electrically connected to the pulsating output terminal Net_C, and the third end of the auxiliary boost module 12 is electrically connected to the second pre-stage output terminal Net_B; the auxiliary boost module 12 is used to boost a voltage between its first end and its second end, and between its second end and its third end during the charging stage of the basic boost-type DC-DC converter; during the discharging stage of the basic boost-type DC-DC converter, the output voltage of the basic boost-type DC-DC converter is transmitted to the other between its second end and its first end, and between its second end and its third end.

[0044] Specifically, the basic boost DC-DC converter has a basic boost function, and can amplify the voltage input by its first input terminal Vin+ and its second input terminal Vin- and output it by its first front-stage output terminal Net_A and its second front-stage output terminal Net_B. It can be understood that the first input terminal Vin+ and the second input terminal Vin- can be connected to a power supply. The basic boost DC-DC converter 11 internally includes a first inductor L1 and a first diode D1, the first inductor L1 is an energy storage element, and the first diode D1 is an anti-reverse current element. Typically, the working process of the basic boost DC-DC converter 11 includes a charging stage and a discharging stage. In the charging stage, the first inductor in the basic boost DC-DC converter 11 is charged by the power supply, and energy is stored in the first inductor L1 at this time, and the first diode D1 can prevent the output element of the basic boost DC-DC converter 11 from only supplying voltage to its first front-stage output terminal and its second front-stage output terminal; in the discharging stage, the energy stored in the first inductor L1 is transmitted to the output element, so that the voltage between the two front-stage output terminals of the basic boost DC-DC converter 11 is boosted. It can be seen that the common connection point of the first inductor L1 and the first diode D1 (that is, the pulsating output terminal Net_B defined in this embodiment) has a voltage pulsation, that is, there will be a voltage increase process and a voltage stabilization process. In addition, the common connection point of the first inductor L1 and the first diode D1 will also provide different connection paths in the charging stage and the discharging stage. Therefore, in this embodiment, by setting the auxiliary boost module 12, it uses the different branches provided by the pulsating output terminal Net_B to achieve different boosting methods in different stages to achieve further boosting. More specifically, during the charging stage, the current between the second end and the first end (or the second end and the third end) of the auxiliary boost module 12 increases linearly to store energy; during the discharging stage, the stored energy is released between the second end and the first end (or the second end and the third end), thereby further boosting the output voltage of the basic boost DC-DC converter to obtain the first output voltage; at the same time, during the discharging stage, the output voltage of the basic boost DC-DC converter is input between the second end and the third end (or the second end and the first end) of the auxiliary boost module 12 to obtain the second output voltage. The load is powered by the superposition of the first output voltage and the second output voltage, thereby making the voltage boost type non-isolated DC-DC conversion circuit have a higher boost capability. And because the auxiliary boost module is connected to the pulsating output end, no additional switch tube is required, so it does not increase the control difficulty, cost and volume.

[0045] The technical solution of this embodiment can increase the boost capability by setting up an auxiliary boost module and using the output voltage of the basic boost-type DC-DC converter and the internal nodes as the boost sources of the auxiliary boost module, without the need to add extra switching transistors. Therefore, the boost capability can be improved without increasing the control complexity, cost, and volume.

[0046] The above is the core idea of the present invention. Below, several specific implementation structures of the basic boost-type DC-DC converter and the specific implementation structure of the auxiliary boost module will be introduced.

[0047] Embodiment 2

[0048] Figure 2 FIG. is a schematic circuit diagram of an auxiliary boost module provided in Embodiment 2 of the present invention, referring to Figure 2 . The auxiliary boost module includes a second diode D sub1 , a first capacitor C sub1 , a second capacitor C sub2 , and a second inductor L sub1 ; the anode of the second diode D sub1 is electrically connected to the first terminal Net_a of the auxiliary boost module, the cathode of the second diode D sub1 is electrically connected to the first terminal of the first capacitor C sub1 , the second terminal of the first capacitor C sub1 is electrically connected to the second terminal Net_b of the auxiliary boost module, the first terminal of the second capacitor C sub2 is electrically connected to the second terminal Net_b of the auxiliary boost module, the second terminal of the second capacitor C sub2 is electrically connected to the first terminal of the second inductor L sub1 , the second terminal of the second inductor L sub1 is electrically connected to the third terminal Net_c of the auxiliary boost module; the auxiliary boost module is used to boost the voltage between its second terminal Net_b and its first terminal Net_a during the charging stage of the basic boost-type DC-DC converter; and transmit the output voltage of the basic boost-type DC-DC converter between the second terminal Net_b and the third terminal Net_c during the discharging stage of the basic boost-type DC-DC converter.

[0049] Specifically, in this embodiment, the auxiliary boost module has an L-C-C-D structure, which can be understood as a common cathode boosting network. During the charging stage of the basic boost-type DC-DC converter, energy is stored through the second inductor L sub1 , and the current of the second inductor L sub1 increases linearly; during the discharging stage, the energy stored in the second inductor L sub1 is released to the second capacitor C sub2 , causing the voltage of the second capacitor C sub2Boost the voltage to obtain a first output voltage; meanwhile, during the discharging stage, the first capacitor C sub1 receives the output voltage of the basic boost DC-DC converter to obtain a second output voltage. By setting the first capacitor C sub1 and the second capacitor C sub2 to supply power to the load together, that is, taking the first end of the first capacitor C sub1 as the first output end of the voltage-boosting non-isolated DC-DC conversion circuit, and taking the second end of the second capacitor C sub2 as the second output end of the voltage-boosting non-isolated DC-DC conversion circuit, a higher output voltage can be obtained. Additionally, it should be noted that the function of the second diode D sub1 is to prevent reverse current, and its specific reverse current prevention principle will be described later.

[0050] Embodiment 3

[0051] Figure 3 is a schematic circuit diagram of an auxiliary boost module provided by Embodiment 3 of the present invention. Refer to Figure 3 . The auxiliary boost module includes a second diode D sub1 , a first capacitor C sub1 , a second capacitor C sub2 , and a second inductor L sub1 ; the first end of the second inductor L sub1 is electrically connected to the first end Net_a of the auxiliary boost module, the second end of the second inductor L sub1 is electrically connected to the first end of the first capacitor C sub1 , the second end of the first capacitor C sub1 is electrically connected to the second end Net_b of the auxiliary boost module, the first end of the second capacitor C sub2 is electrically connected to the second end of the auxiliary boost module, the second end of the second capacitor C sub2 is electrically connected to the anode of the second diode D sub1 , and the cathode of the second diode D sub1 is electrically connected to the third end Net_c of the auxiliary boost module; the auxiliary boost module is used to boost the voltage between its second end and its third end during the charging stage of the basic boost DC-DC converter; and transmit the output voltage of the basic boost DC-DC converter between its second end and its first end during the discharging stage of the basic boost DC-DC converter.

[0052] Specifically, in this embodiment, the auxiliary boost module is also of an L-C-C-D structure, which can be understood as a common anode boost network. During the charging stage of the basic boost DC-DC converter, energy is stored through the second inductor L sub1 , and the current of the second inductor L sub1 increases linearly; during the discharging stage, the second inductor L sub1The stored energy is released to the first capacitor C sub1 so that the first capacitor C sub1 boosts the voltage to obtain a first output voltage; meanwhile, during the discharging stage, the second capacitor C sub2 receives the output voltage of the basic boost DC-DC converter to obtain a second output voltage. By setting the first capacitor C sub1 and the second capacitor C sub2 to supply power to the load together, that is, taking the first end of the first capacitor C sub1 as the first output end of the voltage boost non-isolated DC-DC conversion circuit, and taking the second end of the second capacitor C sub2 as the second output end of the voltage boost non-isolated DC-DC conversion circuit, a higher output voltage can be obtained. Additionally, it should be noted that the function of the second diode D sub1 is to prevent reverse current, and its specific reverse current prevention principle will be described later.

[0053] Embodiment 4

[0054] Figure 4 FIG. is a schematic circuit diagram of a voltage boost non-isolated DC-DC conversion circuit provided by Embodiment 4 of the present invention after being connected to a load and a power supply, referring to Figure 4 . The auxiliary boost module in this embodiment is analyzed taking the common anode boost network as an example.

[0055] The basic boost DC-DC converter further includes a switching transistor K1 and a third capacitor C1; the second end of the first inductor L 1 serves as the first power input end of the basic boost DC-DC converter 11; the first end of the switching transistor K1 is electrically connected to the pulsating output end Net_B, the second end of the switching transistor K1 serves as the second power input end of the basic boost DC-DC converter, and the control end of the switching transistor K1 is connected to the control signal S M ; the first end of the third capacitor C1 is electrically connected to the second end of the first diode D 1 and the first pre-stage output end Net_A, and the second end of the third capacitor C1 is electrically connected to the second end of the switching transistor K1 and the second pre-stage output end Net_B.

[0056] Specifically, first, it is assumed that the control signal S M input to the control end of the switching transistor is an ideal PWM pulse width modulation signal; all power transistors (switching transistors) and filtering elements (capacitors) are ideal devices; the first capacitor, the second capacitor, and the third capacitor are large enough, and their ripples are negligible.

[0057] Based on the above assumptions, the working process of the basic boost DC-DC converter 11 in the steady state is divided into two modes, as shown in Figure 5 and Figure 6 , whereFigure 5 is Figure 4 the state diagram in the first mode, Figure 6 is Figure 4 the state diagram in the second mode.

[0058] In the first mode, the switching transistor is turned on, and the anode of the first diode D 1 is connected to the negative terminal of the power supply Vin (e.g., grounded). The anode of the first diode D 1 is at a low potential. The cathode potential of the first diode D1 is the potential of the third capacitor C1. Therefore, the first diode D 1 is turned off; and the second diode D sub1 also bears a reverse voltage and is cut off. The terminal voltages of the first inductor L 1 and the second inductor L sub1 are U in and U in -U Csub1 , respectively, where U in is the voltage across the power supply Vin, U C1 is the voltage across the third capacitor C1, U Csub1 is the voltage across the first capacitor C sub1 , and U in and U C1 -U Csub1 are both greater than 0. The currents of the first inductor and the second inductor both start to increase linearly;

[0059] In the second mode, the switching transistor is turned off, and the first diode D1 and the second diode Dsub1 are turned on. At this time, the terminal voltages of the first inductor L 1 and the second inductor L sub1 are U in -U C1 and -U Csub1 , respectively, both of which are less than 0, causing the currents of the first inductor L1 and the second inductor L sub1 to start to decrease linearly and charge the corresponding capacitors.

[0060] In addition, assuming that the output voltage of the basic boost DC-DC converter is stable at U C1 , it is well known to those skilled in the art that: where D is the duty cycle of the control signal S M , and U in is the voltage of the power supply V in . In the first mode, the terminal voltage of the second inductor L sub1 is the voltage difference between the voltage of the third capacitor and the voltage of the first capacitor, that is, where L is the inductance value of the second inductor, ΔI L is the current flowing through the second inductor, and T Sis the period of the control signal. When the switching transistor is turned off, the terminal voltage of the second inductor is: According to the volt-second balance, that is, the inductor current cannot change suddenly, U can be solved. Csub1 = DU C1 ; then the voltage U o output by the voltage-boosting non-isolated DC-DC conversion circuit to the load RL is: U o = U Csub1 + U Csub2 = (1 + D)U C1 , substituting into the above formula gives

[0061] In summary, compared with the voltage gain of the basic boost DC-DC converter, the voltage gain of the voltage-boosting non-isolated DC-DC conversion circuit is increased by (1 + D) times. Therefore, under the same input voltage, a higher voltage output capacity can be obtained.

[0062] In addition, the voltage borne by the switching transistor when it is turned off is U C1 , and its voltage stress is the same as that of the corresponding basic boost DC-DC converter without adding an auxiliary boost module. The voltage stresses of the first diode and the second diode in the auxiliary boost module are also U C1 . Therefore, this embodiment can also improve the voltage gain without increasing the voltage stress.

[0063] Embodiment 5

[0064] Figure 7 is a schematic circuit diagram of a voltage-boosting non-isolated DC-DC conversion circuit provided by Embodiment 5 of the present invention. Refer to Figure 7 . The basic boost DC-DC converter further includes a switching transistor K1 and a third capacitor C1; the first end of the switching transistor K1 serves as the first power input end of the basic boost DC-DC converter, the second end of the switching transistor K1 is electrically connected to the pulsating output end Net_B, and the control end of the switching transistor K1 is connected to a control signal; the second end of the first inductor L 1 serves as the second power input end of the basic boost DC-DC converter; the first end of the third capacitor C1 is electrically connected to the second end of the first diode D1 and the second pre-stage input end Net_C, and the second end of the third capacitor C1 is electrically connected to the second end of the first inductor and the first pre-stage output end Net_A.

[0065] Specifically, the working process of the basic boost DC-DC converter in this embodiment also includes a charging stage and a discharging stage. The switching transistor is turned on during the charging stage and turned off during the discharging stage. Referring to the analysis in Embodiment 4, by analyzing the first inductor L 1Voltage across both ends, second inductor L sub1 Based on the voltage across both ends and the volt-second balance principle, the voltage across the load RL and the voltage across the power supply Vin satisfy the following relationship: And the output voltage of the basic boost DC-DC converter and the voltage across the power supply Vin satisfy the following relationship It can be seen that after adding the auxiliary boost module, the voltage gain of the voltage-boosting non-isolated DC-DC converter can be doubled.

[0066] Embodiment Six

[0067] Figure 8 FIG. is a schematic circuit diagram of a voltage-boosting non-isolated DC-DC conversion circuit provided by Embodiment Six of the present invention for reference Figure 8 . The basic boost DC-DC conversion circuit further includes a switching transistor, a third capacitor C1, a third inductor L 2 and a fourth capacitor C2; the first end of the third inductor L 2 serves as the first power input terminal of the basic boost DC-DC converter, the second end of the third inductor L 2 is electrically connected to the first end of the fourth capacitor C2, and the second end of the fourth capacitor C2 is electrically connected to the pulsating output terminal Net_B; the first end of the switching transistor K1 is electrically connected to the second end of the third inductor L 2 , the second end of the switching transistor K1 serves as the second power input terminal of the basic boost DC-DC converter, and the control terminal of the switching transistor K1 receives a control signal; the second end of the first inductor is electrically connected to the second power input terminal; the first end of the third capacitor is electrically connected to the second end of the first diode and the first pre-stage output terminal Net_A, and the second end of the third capacitor C1 is electrically connected to the second end of the switching transistor and the second pre-stage output terminal Net_B.

[0068] Specifically, similar to the above embodiment, the working process of the basic boost DC-DC converter in this embodiment also includes a charging stage and a discharging stage. The switching transistor is turned on during the charging stage and turned off during the discharging stage. Referring to the analysis in Embodiment Four, by analyzing the voltage across the first inductor L 1 across both ends, the voltage across the second inductor L sub1 across both ends, and based on the volt-second balance principle, the voltage across the load RL and the voltage across the power supply Vin satisfy the following relationship: And the output voltage of the basic boost DC-DC converter and the voltage across the power supply Vin satisfy the following relationship It can be seen that after adding the auxiliary boost module, the voltage gain of the voltage-boosting non-isolated DC-DC converter can be doubled.

[0069] Embodiment Seven

[0070] Figure 9 Schematic diagram of the circuit structure of a voltage-boosting non-isolated DC-DC conversion circuit provided in Embodiment 7 of the present invention. Refer to Figure 9 . The basic boost DC-DC converter further includes a switching transistor K1, a third capacitor C1, a third inductor L 2 and a fourth capacitor C2; the first end of the switching transistor K1 serves as the first power input terminal of the basic boost DC-DC converter, the second end of the switching transistor K1 is electrically connected to the first end of the fourth capacitor C2, the control end of the switching transistor K1 receives a control signal, and the second end of the fourth capacitor C2 is electrically connected to the pulsating output terminal Net_B; the first end of the third inductor L 2 is electrically connected to the first end of the fourth capacitor C2, and the second end of the third inductor L 2 serves as the second power input terminal of the basic boost DC-DC converter; the second end of the first diode D 1 is electrically connected to the second pre-stage output terminal Net_C; the first end of the third capacitor C1 is electrically connected to the second end of the first inductor L 1 and the first pre-stage output terminal Net_A, and the second end of the third capacitor is electrically connected to the second end of the first diode and the second pre-stage output terminal Net_C.

[0071] Specifically, similar to the above embodiment, the working process of the basic boost DC-DC converter in this embodiment also includes a charging stage and a discharging stage. The switching transistor is turned on during the charging stage and turned off during the discharging stage. Referring to the analysis in Embodiment 4, by analyzing the voltages across the first inductor L 1 and the second inductor L sub1 and according to the volt-second balance principle, the voltage across the load RL and the voltage across the power supply Vin satisfy the following relationship: And the output voltage of the basic boost DC-DC converter and the voltage across the power supply Vin satisfy the following relationship It can be seen that after adding the auxiliary boost module, the voltage gain of the voltage-boosting non-isolated DC-DC converter can be doubled.

[0072] Embodiment 8

[0073] Figure 10 Schematic diagram of the circuit structure of a voltage-boosting non-isolated DC-DC conversion circuit provided in Embodiment 8 of the present invention. Refer to Figure 10 . The basic boost DC-DC converter further includes a switching transistor K1, a third capacitor C1, a third inductor L 2 and a fourth capacitor C2; the first end of the third inductor L 2 serves as the first power input terminal of the basic boost DC-DC converter, and the first end of the third inductor L 2The second end of is electrically connected to the first end of the fourth capacitor C2, and the second end of the fourth capacitor C2 is electrically connected to the second pre-stage output terminal Net_C; the first end of the switching transistor K1 is electrically connected to the pulsating output terminal Net_B, and the second end of the switching transistor K1 is electrically connected to the second end of the third inductor L 2 ; the control terminal of the switching transistor K1 receives a control signal; the second end of the first inductor L 1 serves as the second power input terminal of the basic boost DC-DC converter; the second end of the first diode D 1 is electrically connected to the second pre-stage output terminal Net_C; the first end of the third capacitor C1 is electrically connected to the second pre-stage output terminal Net_C, and the second end of the third capacitor C1 is electrically connected to the second end of the first inductor L 1 and the first pre-stage output terminal Net_A.

[0074] Specifically, similar to the above embodiment, the working process of the basic boost DC-DC converter in this embodiment also includes a charging stage and a discharging stage. The switching transistor is turned on during the charging stage and turned off during the discharging stage. Referring to the analysis in Embodiment 4, by analyzing the voltages across the first inductor L 1 and the second inductor L sub1 and according to the volt-second balance principle, the voltage across the load RL and the voltage across the power supply Vin satisfy the following relationship: And the output voltage of the basic boost DC-DC converter and the voltage across the power supply Vin satisfy the following relationship It can be seen that after adding the auxiliary boost module, the voltage gain of the voltage-boosting non-isolated DC-DC converter can be doubled.

[0075] Embodiment 9

[0076] The embodiment of the present invention also provides a construction method for a voltage-boosting non-isolated DC-DC conversion circuit, as Figure 11 shown. Figure 11 is a flowchart of a construction method for a voltage-boosting non-isolated DC-DC conversion circuit provided by Embodiment 9 of the present invention. The method includes:

[0077] Step S110, obtaining the first pre-stage output terminal, the second pre-stage output terminal, and the pulsating output terminal of the basic boost DC-DC converter; wherein, the basic boost DC-DC converter includes a first inductor and a first diode connected in series between the first pre-stage output terminal and the second pre-stage output terminal, and the first end of the first inductor and the first end of the first diode are connected to the pulsating output terminal;

[0078] Step S120: Connect the first end of the auxiliary boost module to the first pre-stage output end, connect the second end of the auxiliary boost module to the pulsating output end, and connect the third end of the auxiliary boost module to the second pre-stage output end; wherein, the auxiliary boost module is used to boost the voltage between its second end and its first end, and between its second end and its third end during the charging stage of the basic boost-type DC-DC converter; and transfer the output voltage of the basic boost-type DC-DC converter to the other one between its second end and its first end, and between its second end and its third end during the discharging stage of the basic boost-type DC-DC converter.

[0079] Specifically, in this embodiment, based on the basic boost-type DC-DC converter, the gain is increased by adding an auxiliary boost module. The specific method of increasing the gain can refer to the description of the above embodiment and will not be elaborated here. By setting the auxiliary boost module and using the output voltage of the basic boost-type DC-DC converter and the internal nodes as the boost source of the auxiliary boost module, the boost ability can be increased without adding additional switching transistors, thus improving the boost ability without increasing the control difficulty, cost, and volume.

[0080] Optionally, in the above embodiment, the auxiliary boost module includes a second diode, a first capacitor, a second capacitor, and a second inductor; the anode of the second diode is electrically connected to the first end of the auxiliary boost module, the cathode of the second diode is electrically connected to the first end of the first capacitor, the second end of the first capacitor is electrically connected to the second end of the auxiliary boost module, the first end of the second capacitor is electrically connected to the second end of the auxiliary boost module, the second end of the second capacitor is electrically connected to the first end of the second inductor, and the second end of the second inductor is electrically connected to the third end of the auxiliary boost module;

[0081] Or, the auxiliary boost module includes a second diode, a first capacitor, a second capacitor, and a second inductor; the first end of the second inductor is electrically connected to the first end of the auxiliary boost module, the second end of the second inductor is electrically connected to the first end of the first capacitor, the second end of the first capacitor is electrically connected to the second end of the auxiliary boost module, the first end of the second capacitor is electrically connected to the second end of the auxiliary boost module, the second end of the second capacitor is electrically connected to the anode of the second diode, and the cathode of the second diode is electrically connected to the third end of the auxiliary boost module.

[0082] In addition, the present invention conducts experimental verification on the voltage-boosting non-isolated DC-DC conversion circuit shown in Embodiment 4. Among them, the range of the power input voltage Uin is 20V - 100V, the output voltage Uo = 200V, both the first inductor and the second inductor are 100 μH, and the first capacitor, the second capacitor, and the third capacitor are all 100 μF.

[0083] Figure 12 For Figure 4An experimental waveform diagram of the shown circuit Figure 13 is Figure 4 another experimental waveform diagram of the shown circuit, where Figure 12 the corresponding duty cycle D is 0.33; Figure 13 the corresponding duty cycle D is 0.6. It can be seen that the input voltage and output voltage of the converter satisfy the relationship of U o =(1 + D)*U in / (1 - D); the voltage stresses of the switching transistor S M and the first diode D1 and the second diode D sub1 are all the theoretical analysis values. This shows that the experimental results are completely consistent with the theoretical analysis, thus proving the correctness of the construction method of the voltage-boosting non-isolated DC-DC conversion circuit described above.

[0084] It should be understood that the various forms of processes shown above can be used, with steps reordered, added or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solution of the present invention can be achieved, and no limitations are made herein.

[0085] The above specific embodiments do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A voltage-boosting non-isolated DC-DC conversion circuit, characterized in that, the voltage-boosting non-isolated DC-DC converter includes: a basic boost-type DC-DC converter and an auxiliary boost module; the basic boost-type DC-DC converter includes a first pre-stage output terminal, a second pre-stage output terminal, a first inductor and a first diode connected in series between the first pre-stage output terminal and the second pre-stage output terminal, wherein, a first end of the first inductor and a first end of the first diode are connected in series to a pulsating output terminal; a first end of the auxiliary boost module is electrically connected to the first pre-stage output terminal, a second end of the auxiliary boost module is electrically connected to the pulsating output terminal, and a third end of the auxiliary boost module is electrically connected to the second pre-stage output terminal; the auxiliary boost module is configured to boost the voltage between its second end and its first end, and between its second end and its third end during the charging stage of the basic boost-type DC-DC converter; and transmit the output voltage of the basic boost-type DC-DC converter to the other one between its second end and its first end, and between its second end and its third end during the discharging stage of the basic boost-type DC-DC converter.

2. The voltage-boosting non-isolated DC-DC conversion circuit according to claim 1, characterized in that, the auxiliary boost module includes a second diode, a first capacitor, a second capacitor and a second inductor; an anode of the second diode is electrically connected to the first end of the auxiliary boost module, a cathode of the second diode is electrically connected to a first end of the first capacitor, a second end of the first capacitor is electrically connected to the second end of the auxiliary boost module, a first end of the second capacitor is electrically connected to the second end of the auxiliary boost module, a second end of the second capacitor is electrically connected to a first end of the second inductor, and a second end of the second inductor is electrically connected to the third end of the auxiliary boost module; the auxiliary boost module is configured to boost the voltage between its second end and its first end during the charging stage of the basic boost-type DC-DC converter; and transmit the output voltage of the basic boost-type DC-DC converter to between its second end and its third end during the discharging stage of the basic boost-type DC-DC converter.

3. The voltage-boosting non-isolated DC-DC conversion circuit according to claim 1, characterized in that, the auxiliary boost module includes a second diode, a first capacitor, a second capacitor and a second inductor; a first end of the second inductor is electrically connected to the first end of the auxiliary boost module, a second end of the second inductor is electrically connected to a first end of the first capacitor, a second end of the first capacitor is electrically connected to the second end of the auxiliary boost module, a first end of the second capacitor is electrically connected to the second end of the auxiliary boost module, a second end of the second capacitor is electrically connected to the anode of the second diode, and a cathode of the second diode is electrically connected to the third end of the auxiliary boost module; The auxiliary boost module is used to boost the voltage between its second terminal and third terminal during the charging stage of the basic boost DC-DC converter; and transfer the output voltage of the basic boost DC-DC converter to between its second terminal and first terminal during the discharging stage of the basic boost DC-DC converter.

4. The voltage-boosting non-isolated DC-DC conversion circuit according to claim 1, characterized in that the basic boost DC-DC converter further includes a switching transistor and a third capacitor; the second terminal of the first inductor serves as the first power input terminal of the basic boost DC-DC converter; the first terminal of the switching transistor is electrically connected to the pulsating output terminal, the second terminal of the switching transistor serves as the second power input terminal of the basic boost DC-DC converter, and the control terminal of the switching transistor is connected to a control signal; the first terminal of the third capacitor is electrically connected to the second terminal of the first diode and the first pre-stage output terminal, and the second terminal of the third capacitor is electrically connected to the second terminal of the switching transistor and the second pre-stage output terminal.

5. The voltage-boosting non-isolated DC-DC conversion circuit according to claim 1, characterized in that the basic boost DC-DC converter further includes a switching transistor and a third capacitor; the first terminal of the switching transistor serves as the first power input terminal of the basic boost DC-DC converter, the second terminal of the switching transistor is electrically connected to the pulsating output terminal, and the control terminal of the switching transistor is connected to a control signal; the second terminal of the first inductor serves as the second power input terminal of the basic boost DC-DC converter; the first terminal of the third capacitor is electrically connected to the second terminal of the first diode and the second pre-stage output terminal, and the second terminal of the third capacitor is electrically connected to the second terminal of the first inductor and the first pre-stage output terminal.

6. The voltage-boosting non-isolated DC-DC conversion circuit according to claim 1, characterized in that the basic boost DC-DC converter further includes a switching transistor, a third capacitor, a third inductor and a fourth capacitor; the first terminal of the third inductor serves as the first power input terminal of the basic boost DC-DC converter, the second terminal of the third inductor is electrically connected to the first terminal of the fourth capacitor, and the second terminal of the fourth capacitor is electrically connected to the pulsating output terminal; the first terminal of the switching transistor is electrically connected to the second terminal of the third inductor, the second terminal of the switching transistor serves as the second power input terminal of the basic boost DC-DC converter, and the control terminal of the switching transistor is connected to a control signal; the second terminal of the first inductor is electrically connected to the second power input terminal; the first terminal of the third capacitor is electrically connected to the second terminal of the first diode and the first pre-stage output terminal, and the second terminal of the third capacitor is electrically connected to the second terminal of the switching transistor and the second pre-stage output terminal.

7. The voltage-boosting non-isolated DC-DC conversion circuit according to claim 1, characterized in that The basic boost DC-DC converter further includes a switching transistor, a third capacitor, a third inductor, and a fourth capacitor; the first end of the switching transistor serves as the first power input terminal of the basic boost DC-DC converter, the second end of the switching transistor is electrically connected to the first end of the fourth capacitor, the control end of the switching transistor is connected to a control signal, and the second end of the fourth capacitor is electrically connected to the pulsating output terminal; the first end of the third inductor is electrically connected to the first end of the fourth capacitor, and the second end of the third inductor serves as the second power input terminal of the basic boost DC-DC converter; the second end of the first diode is electrically connected to the second pre-stage output terminal; the first end of the third capacitor is electrically connected to the second end of the first inductor and the first pre-stage output terminal, and the second end of the third capacitor is electrically connected to the second end of the first diode and the second pre-stage output terminal.

8. The voltage boosting non-isolated DC-DC conversion circuit according to claim 1, characterized in that the basic boost DC-DC converter further includes a switching transistor, a third capacitor, a third inductor, and a fourth capacitor; the first end of the third inductor serves as the first power input terminal of the basic boost DC-DC converter, the second end of the third inductor is electrically connected to the first end of the fourth capacitor, and the second end of the fourth capacitor is electrically connected to the second pre-stage output terminal; the first end of the switching transistor is electrically connected to the pulsating output terminal, the second end of the switching transistor is electrically connected to the second end of the third inductor, and the control end of the switching transistor is connected to a control signal; the second end of the first inductor serves as the second power input terminal of the basic boost DC-DC converter; the second end of the first diode is electrically connected to the second pre-stage output terminal; the first end of the third capacitor is electrically connected to the second pre-stage output terminal, and the second end of the third capacitor is electrically connected to the second end of the first inductor and the first pre-stage output terminal.

9. A construction method for a voltage boosting non-isolated DC-DC conversion circuit, characterized in that it includes: obtaining a first pre-stage output terminal, a second pre-stage output terminal, and a pulsating output terminal of a basic boost DC-DC converter; wherein, the basic boost DC-DC converter includes a first inductor and a first diode connected in series between the first pre-stage output terminal and the second pre-stage output terminal, and the first end of the first inductor and the first end of the first diode are connected to the pulsating output terminal; Connect the first end of the auxiliary boost module to the first pre-stage output end, connect the second end of the auxiliary boost module to the pulsating output end, and connect the third end of the auxiliary boost module to the second pre-stage output end; wherein, the auxiliary boost module is used to boost the voltage between its second end and its first end, and between its second end and its third end during the charging stage of the basic boost DC-DC converter; and transfer the output voltage of the basic boost DC-DC converter to the other one between its second end and its first end, and between its second end and its third end during the discharging stage of the basic boost DC-DC converter.

10. The construction method of the voltage-boosting non-isolated DC-DC conversion circuit according to claim 9, characterized in that, the auxiliary boost module includes a second diode, a first capacitor, a second capacitor and a second inductor; the anode of the second diode is electrically connected to the first end of the auxiliary boost module, the cathode of the second diode is electrically connected to the first end of the first capacitor, the second end of the first capacitor is electrically connected to the second end of the auxiliary boost module, the first end of the second capacitor is electrically connected to the second end of the auxiliary boost module, the second end of the second capacitor is electrically connected to the first end of the second inductor, and the second end of the second inductor is electrically connected to the third end of the auxiliary boost module; or, the auxiliary boost module includes a second diode, a first capacitor, a second capacitor and a second inductor; the first end of the second inductor is electrically connected to the first end of the auxiliary boost module, the second end of the second inductor is electrically connected to the first end of the first capacitor, the second end of the first capacitor is electrically connected to the second end of the auxiliary boost module, the first end of the second capacitor is electrically connected to the second end of the auxiliary boost module, the second end of the second capacitor is electrically connected to the anode of the second diode, and the cathode of the second diode is electrically connected to the third end of the auxiliary boost module.

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