Active switch coupling inductor winding direct current boost converter

Abstract

The invention discloses an active switch coupling inductor winding direct-current boost converter, and relates to the field of power electronic inverters. The invention aims to solve the problem that a conventional DC boost converter usually has relatively large inductive current ripples. The direct-current voltage source is directly connected with the coupling inductor N1, so that the input current is continuous and can continuously provide relatively stable energy for the circuit, and the coupling inductor increases the amplification factor of the circuit through the turn ratio, so that the duty ratio of the switching tube is adjusted, and relatively small current ripples can be kept even under the condition that the boost factor is relatively large. The capacitor is charged when the voltage of N2 rises, and the capacitor can avoid the problem of distortion of an output waveform caused by instability such as reduction of the voltage of a direct current link due to instability of inductance voltage caused by discontinuous current during discharging. The charging and discharging characteristics of the capacitor further optimize the voltage distribution, reduce the requirement of obtaining high voltage gain under the condition of large duty ratio in the prior art, and improve the boost capability at the same time.

Description

Technical Field

[0001] The invention belongs to the field of power electronic inverters, and in particular relates to a direct current boost converter. Background Art

[0002] Traditional DC boost converters usually have large inductor current ripple, which can cause electromagnetic interference problems. Excessive current ripple will generate high-frequency noise in the circuit, affecting the normal operation of other electronic devices, and require additional filtering circuits to suppress electromagnetic interference, increasing the cost and volume of the system. Traditional boost converters using a single inductor face difficulties in achieving high boost ratios. In order to achieve a high boost ratio, the duty cycle needs to be close to 1, but this will cause the power switch and diode to be subjected to extreme voltage and current stress, and will also increase the ripple of the inductor current, affecting the stability and reliability of the converter. Summary of the invention

[0003] The present invention aims to solve the problem that a conventional DC boost converter usually has a large inductor current ripple, and provides an active switch coupled inductor winding DC boost converter.

[0004] An active switch coupled inductor winding DC boost converter includes: power switch tubes S1 and S2, diodes D1-D3, capacitor C1, inductor L1, coupled inductor windings N1 and N2, output diode D o and output capacitor C o ;

[0005] The positive electrode of the coupled inductor winding N1 is used to connect to the positive electrode of the DC power supply.

[0006] The cathode of the coupled inductor winding N1 is connected to the anode of the coupled inductor winding N2 and the anode of the diode D1 respectively.

[0007] The cathode of the coupled inductor winding N2 is connected to the anode of the diode D2.

[0008] The cathode of diode D2 is connected to one end of inductor L1 and the source of power switch S1.

[0009] The other end of the inductor L1 is connected to the cathode of the diode D1, the anode of the diode D3, and the output diode D o The positive electrode and the drain of the power switch tube S2,

[0010] The drain of the power switch tube S1 and the cathode of the diode D3 are connected to one end of the capacitor C1 at the same time.

[0011] Output diode D o The negative terminal of the output capacitor C o One end of

[0012] Output capacitor Co The two ends of the load are connected as follows.

[0013] The other end of capacitor C1, output capacitor C o The other end of the power switch tube S2 and the source of the power switch tube S2 are used to connect the negative electrode of the DC voltage source.

[0014] Furthermore, the voltage gain G of the active switch coupled inductor winding DC boost converter is expressed as:

[0015]

[0016] Wherein, D is the on-duty cycle of the power switch tubes S1 and S2, and n1 is the turns ratio of the coupled inductor windings N1 and N2.

[0017] Furthermore, the turns ratio n1 of the coupled inductor windings N1 and N2 is n1=2.

[0018] Furthermore, the operating range of the on-duty cycle D of the power switches S1 and S2 is (0, 0.5).

[0019] Furthermore, the active switch coupled inductor winding DC boost converter includes two operating modes, namely:

[0020] When the power switches S1 and S2 are turned on, the DC voltage source V in To charge the coupled inductor winding N1, the diode D2 is reverse biased and cut off, the diode D1 is turned on, the capacitor C1 charges the inductor L1 through the power switch tube S1, and the diode D3 and the output diode D o Both are reverse biased and cut off, the output capacitor C o Provide independent power supply for load resistor R;

[0021] When the power switches S1 and S2 are turned off, diodes D2 and D3 are both turned on, diode D1 is reverse biased and cut off, and the DC voltage source V in , inductor L1, coupled inductor windings N1 and N2 charge capacitor C1, and the DC voltage source V in , inductor L1, coupled inductor windings N1 and N2 through output diode D o is the load resistance R and the output capacitance C o powered by.

[0022] The active switch coupled inductor winding DC boost converter proposed by the present invention has a DC voltage source V inDirectly connecting the coupled inductor N1 makes the input current continuous and can continuously provide relatively stable energy to the circuit. The coupled inductor increases the amplification factor of the circuit through the effect of the turns ratio, thereby adjusting the duty cycle of the switch tube, and maintaining a small current ripple even when the boost multiple is large. At the same time, due to the principle of magnetic induction, the voltage of N2 increases to charge the capacitor C1. When discharging, the capacitor C1 can avoid the instability of the inductor voltage caused by the discontinuous current, which in turn causes the DC link voltage to drop and other instabilities, thereby causing the output waveform to be distorted. In addition, the charging and discharging characteristics of the capacitor C1 further optimize the voltage distribution, reduce the previous requirement to obtain high voltage gain under large duty cycles, and improve the boost capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The circuit structure diagram of the active switch coupled inductor winding DC boost converter;

[0024] Figure 2 is the equivalent circuit diagram of the active switch coupled inductor winding DC boost converter, where (a) represents the switch on, and (b) represents the switch off;

[0025] Figure 3 The experimental waveforms are shown in Figure 2, where (a) represents the output capacitor voltage and input voltage, (b) represents the output diode and power switch tube voltage, (c) represents the inductor and coupled inductor winding current, and (d) represents the capacitor and diode voltage. DETAILED DESCRIPTION

[0026] 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.

[0027] Reference Figure 1 Specifically describe this embodiment, the active switch coupled inductor winding DC boost converter described in this embodiment includes: power switch tubes S1 and S2, diodes D1-D3, capacitor C1, inductor L1, coupled inductor windings N1 and N2, output diode D o and output capacitor C o .

[0028] DC voltage source V inThe positive electrode of the coupled inductor winding N1 is connected to the positive electrode of the coupled inductor winding N1, the negative electrode of the coupled inductor winding N1 is connected to the positive electrode of the coupled inductor winding N2 and the positive electrode of the diode D1, the negative electrode of the coupled inductor winding N2 is connected to the positive electrode of the diode D2, the negative electrode of the diode D2 is connected to one end of the inductor L1 and the source of the power switch tube S1, and the other end of the inductor L1 is connected to the negative electrode of the diode D1, the positive electrode of the diode D3, and the output diode D o The positive electrode of the power switch tube S2 and the drain of the power switch tube S1 and the negative electrode of the diode D3 are connected to one end of the capacitor C1 at the same time, and the output diode D o The negative terminal of the output capacitor C o Output capacitor C o The two ends of the capacitor are used to connect the load resistor R. The other end of the capacitor C1, the output capacitor C o The other end of the power switch tube S2 and the source of the power switch tube S2 are connected to the DC voltage source V in of the negative electrode.

[0029] The working principle and working process of the active switch coupled inductor winding DC boost converter described in this embodiment are as follows:

[0030] The active switch coupled inductor winding DC boost converter described in this embodiment uses the control signal V gs Control the on and off of the power switch tubes S1 and S2. The currents flowing through the inductor L1, coupled inductor windings N1 and N2 are i L1 、i N1 and i N2 ; The voltages of diodes D1~D3 and capacitor C1 are V D1 、V D2 、V D3 、V C1 ; Output diode D o The voltage is V Do , its working process is divided into two switching modes: switch on and switch off, which are described as follows:

[0031] When the power switches S1 and S2 are turned on, the equivalent circuit is as follows: Figure 2 (a) shows that at this stage, the DC voltage V in The coupled inductor winding N1 is charged. Due to the principle of magnetic induction, the diode D2 is reverse biased and cut off, and the diode D1 is turned on. At the same time, the capacitor C1 charges the inductor L1 through the power switch tube S1, and the diode D3 is reverse biased and cut off. The output diode D o Reverse bias cutoff, output capacitor C o The load resistor R is powered independently and this mode ends.

[0032] When the power switches S1 and S2 are turned off, the equivalent circuit is as follows: Figure 2As shown in (b), at this stage, diodes D2 and D3 are turned on, diode D1 is reverse biased and cut off, and the DC voltage source V in , inductor L1, coupled inductor windings N1 and N2 charge capacitor C1; at the same time, the DC voltage source V in , inductor L1, coupled inductor windings N1 and N2 through output diode D o Give the load resistor R and output capacitor C o Power is supplied and this mode ends.

[0033] From the above analysis, we can obtain a higher voltage gain. The expression of voltage gain G is:

[0034]

[0035] Wherein, D is the conduction duty cycle of the power switch tubes S1 and S2, and its operating range is (0,0.5). n1 is the turns ratio of the coupled inductor windings N1 and N2, and n1=N2:N1.

[0036] The beneficial effects of the structure of this embodiment are illustrated by the data of specific experiments:

[0037] like Figure 3 As shown, the input voltage V in =50V, the output voltage is about V o =450V, the on-duty cycle of power switch tubes S1 and S2 is D=0.4, n1=2, and the load resistance R=200Ω.

[0038] Figure 3 (a) is a schematic diagram of an output capacitor voltage of 450V and an input voltage of 50V;

[0039] Figure 3 (b) is the output diode D o and the curve diagram of the power switch tube voltage;

[0040] Figure 3 (c) is a graph of the current of the inductor L1 and the coupled inductor winding N1;

[0041] Figure 3 (d) is a graph of the voltages of capacitor C1 and diode D3.

[0042] from Figure 3 It can be seen that the active switch coupled inductor winding DC boost converter has a very high output gain.

[0043] In summary, the active switch coupled inductor winding DC boost converter proposed in this embodiment, the DC voltage source V inDirectly connecting the coupled inductor N1 makes the input current continuous and can continuously provide relatively stable energy to the circuit. The coupled inductor increases the amplification factor of the circuit through the effect of the turns ratio, thereby adjusting the duty cycle of the switch tube, and maintaining a small current ripple even when the boost multiple is large. At the same time, due to the principle of magnetic induction, the voltage of N2 increases to charge the capacitor C1. When discharging, the capacitor C1 can avoid the instability of the inductor voltage caused by the discontinuous current, which in turn causes the DC link voltage to drop and other instabilities, thereby causing the output waveform to be distorted. In addition, the charging and discharging characteristics of the capacitor C1 further optimize the voltage distribution, reduce the previous requirement to obtain high voltage gain under large duty cycles, and improve the boost capability.

[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 switch coupled inductor winding DC boost converter, characterized in that: include: Power switch tubes S1 and S2, diodes D1~D3, capacitor C1, inductor L1, coupled inductor windings N1 and N2, output diode D o and output capacitor C o ; The positive electrode of the coupled inductor winding N1 is used to connect to the positive electrode of the DC power supply. The cathode of the coupled inductor winding N1 is connected to the anode of the coupled inductor winding N2 and the anode of the diode D1 respectively. The cathode of the coupled inductor winding N2 is connected to the anode of the diode D2. The cathode of diode D2 is connected to one end of inductor L1 and the source of power switch S1. The other end of the inductor L1 is connected to the cathode of the diode D1, the anode of the diode D3, and the output diode D o The positive electrode and the drain of the power switch tube S2, The drain of the power switch tube S1 and the cathode of the diode D3 are connected to one end of the capacitor C1 at the same time. Output diode D o The negative terminal of the output capacitor C o One end of Output capacitor C o The two ends of the load are connected as follows. The other end of capacitor C1, output capacitor C o The other end of the power switch tube S2 and the source of the power switch tube S2 are used to connect the negative electrode of the DC voltage source.

2. The active switch coupled inductor winding DC boost converter according to claim 1, characterized in that: The voltage gain G of the active switch coupled inductor winding DC boost converter is expressed as: Wherein, D is the on-duty cycle of the power switch tubes S1 and S2, and n1 is the turns ratio of the coupled inductor windings N1 and N2.

3. The active switch coupled inductor winding DC boost converter according to claim 2, characterized in that: The turns ratio n1 of the coupled inductor windings N1 and N2 is n1=2.

4. The active switch coupled inductor winding 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, 0.5).

5. The active switch coupled inductor winding DC boost converter according to claim 1, 2, 3 or 4, characterized in that: The active switch coupled inductor winding DC boost converter includes two working modes, namely: When the power switches S1 and S2 are turned on, the DC voltage source V in To charge the coupled inductor winding N1, the diode D2 is reverse biased and cut off, the diode D1 is turned on, the capacitor C1 charges the inductor L1 through the power switch tube S1, and the diode D3 and the output diode D o Both are reverse biased and cut off, the output capacitor C o Provide independent power supply for load resistor R; When the power switches S1 and S2 are turned off, diodes D2 and D3 are both turned on, diode D1 is reverse biased and cut off, and the DC voltage source V in , inductor L1, coupled inductor windings N1 and N2 charge capacitor C1, and the DC voltage source V in , inductor L1, coupled inductor windings N1 and N2 through output diode D o is the load resistance R and the output capacitance C o powered by.

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