Active double-switch inductor direct-current boost converter

Abstract

The invention discloses an active double-switch inductance direct-current boost converter, and relates to the field of power electronic inverters. The invention aims to solve the problem that the traditional direct current boost converter has higher power loss. The direct-current voltage source Vin is directly connected with the inductor L1 and can continuously provide relatively stable energy for the circuit, so that waveform changes such as the voltage of the output capacitor Co and the voltage of a direct-current link are relatively stable. The power switch is used to enable the converter to have a plurality of working modes, the working modes are divided into an on state and an off state, voltage distribution is further optimized, the working mode enables elements to bear appropriate voltages at different stages, some elements are prevented from bearing overhigh voltages, the voltage stress of the elements is reduced, and the voltage distribution efficiency is improved. And the energy conversion efficiency and the boosting capability are further improved. Meanwhile, the conduction duty ratio range of the power switch is adjustable, the diversity of control strategies is increased, and different application scenes can be adapted by changing different conduction duty ratios.

Description

Technical Field

[0001] The invention belongs to the field of power electronic inverters. Background Art

[0002] Traditional DC boost converters, such as the basic Boost converter, have large power losses during the boost process. This is mainly due to the single inductor structure and simple switch control strategy. In high boost ratio application scenarios, the conduction loss and switching loss of the power switch device and the diode will increase significantly, resulting in reduced efficiency of the entire converter. Traditional single-inductor boost converters face challenges in achieving high boost ratios. As the boost ratio increases, its duty cycle needs to be close to 1, which will increase the stress on the power switch and diode, and also increase the loss of the converter. Summary of the invention

[0003] The present invention aims to solve the problem of large power loss in traditional DC boost converters and provides an active dual-switch inductor DC boost converter.

[0004] An active dual-switch inductor DC boost converter, comprising: a resistor D 1 ~D 9 、Inductance L 1 ~L 4 , power switch tube S 1 , power switch tube S 2 , capacitor C 1 and output unit;

[0005] Inductance L 1 One end and diode D 1 The positive pole of diode D is used to connect the positive pole of power supply. 1 The negative pole of the inductor L 2 One end and diode D 2 The cathode is connected to the inductor L 1 The other end of the diode D 2 The positive electrode and diode D 3 The positive pole is connected to the inductor L 2 The other end of the diode D 3 The cathode of diode D 4 The positive electrode and diode D 5 The positive electrode of diode D 4 The cathode of diode D 6 The positive electrode, inductor L 3 One end and the power switch tube S 1 The source of diode D 6 The cathode of 4 One end and diode D 7 The cathode is connected to the inductor L3 The other end of the diode D 7 The positive electrode and diode D 8 The positive electrode of diode D 5 The cathode of 4 The other end of the diode D 8 The cathode of diode D 9 The positive electrode and power switch tube S 2 The drain of the power switch tube S 1 The drain of diode D 9 The cathode and capacitor C 1 One end of the capacitor C 1 The other end and the power switch tube S 2 The source electrodes are used to be connected to the negative electrode of the power supply, and the output unit is connected in parallel to the power switch tube S 2 between the source and drain and serves as the voltage output terminal.

[0006] Furthermore, the output unit includes an output diode D o and output capacitor C o ;

[0007] Output diode D o The positive pole of the power switch tube S 1 The drain of the output diode D o The cathode of the output capacitor C o One end of the output capacitor C o The other end is connected to the power switch tube S 2 The source of the output capacitor C o Both ends serve as load connection ends.

[0008] Furthermore, the expression of the voltage gain G of the above active dual-switch inductor DC boost converter is:

[0009]

[0010] Where D is the power switch tube S 1 and S 2 The on-duty cycle.

[0011] Furthermore, the power switch tube S 1 and S 2 The operating range of the on-duty cycle D is (0,0.33).

[0012] Furthermore, the power switch tube S 1 and S 2 The on-duty ratio D is 0.3.

[0013] Further, the above-mentioned active dual-switch inductor DC boost converter includes two operating modes, and the two operating modes are respectively that power switch tubes S 1 and S 2 conduct, and power switch tubes S 1 and S 2 turn off.

[0014] Further, in the above-mentioned active dual-switch inductor DC boost converter, in the mode where power switch tubes S 1 and S 2 conduct, the power supply charges inductor L 1 , diodes D 2 and diode D 4 are reverse-biased and cut off, and diodes D 1 , diode D 3 and diode D 5 conduct; at the same time, capacitor C 1 charges inductor L 1 and inductor L 3 through power switch tube S 4 , diodes D 6 and diode D 8 conduct, and diodes D 7 and diode D 9 are reverse-biased and cut off; output diode D o is reverse-biased and cut off, and output capacitor C o powers the load independently.

[0015] Further, in the above-mentioned active dual-switch inductor DC boost converter, in the mode where power switch tubes S 1 and S 2 turn off, diodes D 2 , diode D 4 , diode D 7 and diode D 9 all conduct, diodes D 1 , diode D 3 , diode D 5 , diode D 6 and diode D 8 are all reverse-biased and cut off, and the power supply charges capacitor C 1 through inductor L 2 , inductor L 3 , inductor L 4 and inductor L 1 ; at the same time, the power supply supplies power to the load and output capacitor C 1 through inductor L 2 , inductor L 3 , inductor L 4 , inductor L o and output diode D opowered by.

[0016] The beneficial effects of the active dual-switch inductor DC boost converter described in the present invention are as follows:

[0017] DC voltage source V in Directly connected inductor L 1 Since the inductor current is continuous, it can continuously provide relatively stable energy to the circuit, making the output capacitor C o The waveform changes of voltage, DC link voltage, etc. are relatively stable. Avoid instability of inductor voltage due to current discontinuity, which in turn causes instability such as a drop in DC link voltage, thereby causing distortion of the output waveform. The use of power switches in the converter of the present invention enables the converter to have multiple working modes, and the working modes are divided into an on state and an off state, which further optimizes the voltage distribution. This working mode enables the components to withstand appropriate voltages at different stages, avoiding certain components from being subjected to excessively high voltages, thereby reducing component voltage stress and further improving energy conversion efficiency and boosting capabilities. At the same time, the on-duty cycle range of the power switch is adjustable, which increases the diversity of control strategies, and can be applied to different application scenarios by changing different on-duty cycles. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The circuit structure diagram of an active dual-switch inductor DC boost converter is shown;

[0019] Figure 2 is the equivalent circuit diagram of the active dual-switch inductor DC boost converter, where (a) represents the switch on and (b) represents the switch off;

[0020] Figure 3 The following are experimental waveforms, where (a) is the output capacitor voltage of about 650V and the input voltage of 50V, (b) is the output diode voltage and the power tube voltage, (c) is the inductor current and the diode voltage, and (d) is the capacitor voltage and the diode voltage. DETAILED DESCRIPTION

[0021] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0022] Reference Figure 1 Specifically describing this embodiment, an active dual-switch inductor DC boost converter described in this embodiment includes: a resistor D1 ~D 9 、Inductance L 1 ~L 4 , power switch tube S 1 , power switch tube S 2 , capacitor C 1 , output diode D o and output capacitor C o .

[0023] DC voltage source V in The positive electrode of the inductor L 1 One end and diode D 1 The positive pole is connected;

[0024] Diode D 1 The negative pole of the inductor L 2 One end and diode D 2 The cathode of is connected;

[0025] Inductance L 1 The other end of the diode D 2 The positive electrode and diode D 3 The positive pole is connected;

[0026] Inductance L 2 The other end of the diode D 3 The cathode of diode D 4 The positive electrode and diode D 5 The positive pole is connected;

[0027] Diode D 4 The cathode of diode D 6 The positive electrode, inductor L 3 One end and the power switch tube S 1 The source of is connected;

[0028] Diode D 6 The cathode of 4 One end and diode D 7 The cathode of is connected;

[0029] Inductance L 3 The other end of the diode D 7 The positive electrode and diode D 8 The positive pole is connected;

[0030] Diode D 5 The cathode of 4 The other end of the diode D 8 The cathode of diode D 9 The positive pole of the output diode D o The positive electrode and power switch tube S 2The drain of is connected;

[0031] Power switch tube S 1 The drain of diode D 9 The cathode and capacitor C 1 One end is connected;

[0032] Output diode D o The cathode of the output capacitor C o One end of is connected to one end of the load resistor R;

[0033] The other end of the load resistor R, the output capacitor C o The other end of the capacitor C 1 The other end and the power switch tube S 2 The source of the DC voltage source V in The negative pole is connected.

[0034] The working principle and working process of an active dual-switch inductor DC boost converter described in this embodiment are as follows:

[0035] The working process of this embodiment is divided into two switching modes: switch on and switch off, which are described in detail as follows:

[0036] When the switch is turned on, the equivalent circuit is as follows Figure 2 As shown in (a), at this stage, the power switch tube S 1 and S 2 On, DC voltage source V in Give inductor L 1 Charging, diode D 2 and D 4 Reverse bias cutoff, diode D 1 , D 3 and D 5 At the same time, the capacitor C 1 Through the power switch tube S 1 Give inductor L 3 and L 4 Charging, diode D 6 and D 8 Conducting, diode D 7 and D 9 Reverse bias cutoff; output diode D o Reverse bias cutoff, output capacitor C o The load resistor R is powered independently and this mode ends.

[0037] When the switch is off, the equivalent circuit is as follows Figure 2 As shown in (b), the power switch tube S 1 and S 2 Keep off, diode D 2 , D 4 , D7 and D 9 conducts, and diode D 1 and D 3 and D 5 and D 6 and D 8 is reverse-biased and cut off, and DC voltage source V in charges capacitor C through inductor L 1 and L 2 and L 3 and L 4 ; meanwhile, DC voltage source V 1 powers load resistor R and output capacitor C through inductor L in and L 1 and L 2 and L 3 and L 4 and output diode D o ; this mode ends. o Power supply, this mode ends.

[0038] From the above analysis, the expression of voltage gain G can be obtained as follows:

[0039]

[0040] where D is the conduction duty cycle of power switch tubes S 1 and S 2 , and its working range is (0, 0.33).

[0041] The beneficial effects of adopting this embodiment are illustrated below through specific experimental data:

[0042] As Figure 3 shown, the input voltage is 50V, the output capacitor voltage is about 650V, and the conduction duty cycle of power switch tubes S 1 and S 2 is 0.3, and the load resistor is 200Ω. Figure 3 (a) shows the output capacitor voltage of about 650V and the input voltage of 50V. Figure 3 (b) shows the output diode voltage and the power transistor voltage. Figure 3 (c) shows the inductor current and the diode voltage. Figure 3 (d) shows the capacitor voltage and the diode voltage. It can be seen from the figure that the active dual-switch inductor DC boost converter has a very high output gain.

[0043] In summary, the present invention relates to an active dual-switch inductor DC boost converter, in order to solve the problem that traditional DC boost converters, such as basic Boost converters, have large power losses during the boost process. In high boost ratio application scenarios, the conduction loss and switching loss of the power switch device and the diode will increase significantly, resulting in reduced efficiency of the entire converter. Traditional single-inductor boost converters face challenges in achieving high boost ratios. As the boost ratio increases, its duty cycle needs to be close to 1, which will cause increased stress on the power switch and diode, and will also increase the loss of the converter. The dual-switch inductor of the present invention is composed of L 1 , L 2 , D 1 , D 2 , D 3 , L 3 , L 4 , D 6 , D 7 , D 8 The DC converter output unit consists of an output diode, an output capacitor and a load, which can greatly improve the voltage gain.

[0044] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. An active dual-switch inductor DC boost converter, characterized in that: include: Resistors D1-D9, inductors L1-L4, power switch tube S1, power switch tube S2, capacitor C1 and output unit; One end of the inductor L1 and the positive electrode of the diode D1 are used to connect to the positive electrode of the power supply, the negative electrode of the diode D1 is connected to one end of the inductor L2 and the cathode of the diode D2 respectively, the other end of the inductor L1 is connected to the positive electrode of the diode D2 and the positive electrode of the diode D3 respectively, the other end of the inductor L2 is connected to the cathode of the diode D3, the positive electrode of the diode D4 and the positive electrode of the diode D5 respectively, the cathode of the diode D4 is connected to the positive electrode of the diode D6, one end of the inductor L3 and the source of the power switch tube S1 respectively, the cathode of the diode D6 is connected to one end of the inductor L4 and The cathode of the diode D7 is connected, the other end of the inductor L3 is respectively connected to the anode of the diode D7 and the anode of the diode D8, the cathode of the diode D5 is respectively connected to the other end of the inductor L4, the cathode of the diode D8, the anode of the diode D9 and the drain of the power switch tube S2, the drain of the power switch tube S1 is respectively connected to the cathode of the diode D9 and one end of the capacitor C1, the other end of the capacitor C1 and the source of the power switch tube S2 are used to be connected to the negative electrode of the power supply, and the output unit is connected in parallel between the source and the drain of the power switch tube S2 and serves as a voltage output end.

2. The active dual-switch inductor DC boost converter according to claim 1, characterized in that: The output unit includes an output diode D o and output capacitor C o ; Output diode D o The positive electrode is connected to the drain of the power switch tube S1, and the output diode D o The cathode of the output capacitor C o One end of the output capacitor C o The other end is connected to the source of the power switch tube S2, the output capacitor C o Both ends serve as load connection ends.

3. An active dual-switch inductor DC boost converter according to claim 1 or 2, characterized in that: The expression of the voltage gain G of the active dual-switch inductor DC boost converter is: Wherein, D is the conduction duty cycle of the power switch tubes S1 and S2.

4. The active dual-switch inductor DC boost converter according to claim 3, characterized in that: The operating range of the conduction duty cycle D of the power switch tubes S1 and S2 is (0, 0.33).

5. The active dual-switch inductor DC boost converter according to claim 3, characterized in that: The conduction duty cycle D of the power switch tubes S1 and S2 is 0.

3.

6. An active dual-switch inductor DC boost converter according to claim 1 or 2, characterized in that: The active dual-switch inductor DC boost converter includes two working modes, wherein the two working modes are respectively that the power switch tubes S1 and S2 are turned on and the power switch tubes S1 and S2 are turned off.

7. The active dual-switch inductor DC boost converter according to claim 6, characterized in that: In the mode where the power switch tubes S1 and S2 are turned on, the power supply charges the inductor L1, the diodes D2 and D4 are reverse biased and cut off, and the diodes D1, D3 and D5 are turned on; at the same time, the capacitor C1 charges the inductor L3 and L4 through the power switch tube S1, the diodes D6 and D8 are turned on, and the diodes D7 and D9 are reverse biased and cut off; the output diode D o Reverse bias cutoff, output capacitor C o Provide independent power supply to the load.

8. The active dual-switch inductor DC boost converter according to claim 6, characterized in that: In the mode where the power switches S1 and S2 are turned off, diodes D2, D4, D7 and D9 are all turned on, diodes D1, D3, D5, D6 and D8 are all reverse biased and cut off, and the power supply charges capacitor C1 through inductor L1, inductor L2, inductor L3 and inductor L4; at the same time, the power supply charges capacitor C1 through inductor L1, inductor L2, inductor L3, inductor L4 and output diode D o For the load and output capacitor C o powered by.

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