Coupling inductor square Boost converter

Abstract

The invention discloses a coupling inductance square Boost converter, and belongs to the technical field of power electronic inverters. The problems that a traditional Boost converter bears large voltage stress at a switch, energy loss is caused by correspondingly increasing circuit elements when the boost requirement cannot be met, and inductive current ripples and switch-off current of a switch tube are caused by influence of parasitic parameters of devices are solved. The circuit mainly comprises a DC voltage source Vin, diodes D0 to D4, capacitors C0 to C1, an inductor L1, a coupling inductor and a power switch S, and can greatly improve the voltage gain. The invention is mainly used for DC boost conversion.

Description

Technical Field

[0001] The invention belongs to the technical field of power electronic inverters, and in particular relates to a coupled inductor square Boost converter. Background Art

[0002] Boost converters are widely used in electric vehicles, voltage regulator modules, battery inverters, etc. Under high-frequency switching, the reverse recovery current of the diode of the traditional Boost converter will produce voltage spikes, and the voltage stress at the switch is also quite large, affecting the stability and reliability of the circuit. At the same time, due to the influence of device parasitic parameters, it causes inductor current ripple and switch tube turn-off current, affecting the efficiency and stability of the circuit; when the boost requirements of actual applications cannot be met, the circuit elements will be increased accordingly, resulting in energy loss. The above problems need to be solved urgently. Summary of the invention

[0003] The purpose of the present invention is to solve the problems that the traditional Boost converter is subjected to large voltage stress at the switch, the corresponding increase of circuit elements causes energy loss when the boost requirement cannot be met, and the inductor current ripple and the switch off current of the switch tube are caused by the influence of device parasitic parameters. The present invention provides a coupled inductor square Boost converter.

[0004] A coupled inductor square boost converter including a DC voltage source V in , diodes D0 to D4, capacitors C0 to C1, inductor L1, coupled inductor and power switch S; wherein capacitor C0 serves as an output capacitor, and the voltage across it serves as the output voltage V0 of the Boost converter;

[0005] DC voltage source V in The positive electrode of is connected to the anode of the diode D3 and the same-name end of the primary winding N1 of the coupled inductor at the same time, the opposite-name end of the primary winding N1 of the coupled inductor is connected to the anode of the diode D1 and the same-name end of the secondary winding N2 of the coupled inductor at the same time, the opposite-name end of the secondary winding N2 of the coupled inductor is connected to one end of the capacitor C1, the other end of the capacitor C1 is connected to the anode of the diode D4, the cathode of the diode D1 and the anode of the diode D2 at the same time, the cathode of the diode D4 is connected to the cathode of the diode D3 and one end of the inductor L1 at the same time, the other end of the inductor L1 is connected to the cathode of the diode D2, the drain of the power switch S and the anode of the diode D0 at the same time, and the cathode of the diode D0 is connected to one end of the capacitor C0 and one end of the load resistor R at the same time;

[0006] DC voltage source V in The negative electrode of is connected to the source of the power switch S and the other end of the capacitor C0 and the other end of the load resistor R at the same time.

[0007] Preferably, the voltage gain of the Boost converter Wherein, D is the on-duty cycle of the power switch S, and n1 is the turns ratio of the secondary winding N2 to the primary winding N1 of the coupled inductor.

[0008] Preferably, the Boost converter has two operating modes in one switching cycle, namely an on state and an off state.

[0009] Preferably, in the on-state working mode, the power switch tube S is turned on, and the DC voltage source V in The inductor L1 is charged through the diode D3, and the DC voltage source V in The primary winding N1 of the coupled inductor is charged. Due to the principle of magnetic induction, the secondary winding N2 of the coupled inductor charges the capacitor C1, and the diode D1 is forward-biased and turned on. At the same time, the diodes D4 and D0 are reverse-biased and cut off, the diodes D2 and D3 are forward-biased and turned on, and the capacitor C0 supplies power to the load resistor R.

[0010] Preferably, in the off-state operating mode, the power switch tube S remains off, diodes D1 to D3 are reverse biased and cut off, D4 is forward biased and turned on, and capacitor C1 is discharged. At the same time, inductor L1 and the primary winding N1 of the coupled inductor and its secondary winding N2 supply power to the load resistor R and capacitor C0 through diode D0.

[0011] Preferably, the on-duty cycle adjustment range of the power switch tube S is (0, 1).

[0012] Preferably, the optimal conduction duty cycle of the power switch tube S is 0.4.

[0013] Advantages of the present invention:

[0014] DC voltage source V in Directly connecting the primary winding N1 of the coupled inductor 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 power switch S. Even in the case of a large boost factor, the current ripple can be kept small. At the same time, due to the principle of magnetic induction, the voltage of the secondary winding N2 of the coupled inductor increases to charge the capacitor C1. When discharging, the capacitor C1 avoids the instability of the inductor voltage due to the discontinuous current, which in turn causes the DC link voltage to drop and other instabilities, thereby causing the output waveform to be distorted.

[0015] In addition, the voltage of the diode D3 is much lower than the output voltage, and the current of the primary winding N1 of the inductor L1 and the coupled inductor does not fluctuate greatly, which reduces energy loss, reduces component voltage stress, and reduces circuit current ripple. At the same time, it meets the requirements of fast transient response and adjusts the circuit duty cycle to optimize performance, thereby improving energy conversion efficiency and boost capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the coupled inductor square Boost converter of the present invention;

[0017] Figure 2 is an equivalent circuit diagram of the coupled inductor square Boost converter of the present invention when the power switch S is turned on and off; wherein, Figure 2 a is the equivalent circuit diagram of the coupled inductor square boost converter when the power switch S is turned on. Figure 2 b is the equivalent circuit diagram of the coupled inductor square Boost converter when the power switch S is turned off;

[0018] Figure 3 When the coupled inductor square boost converter of the present invention is used for boost conversion, when the input voltage V in =50V, the experimental waveform diagram when the output voltage V0 = 283V; where,

[0019] Figure 3 a is the input voltage V in =50V and output voltage V0 = 283V;

[0020] Figure 3 b is the voltage V of the output diode D0 D0 The peak value is about 283V and the voltage V of the switching diode S S The peak value is about 283V waveform;

[0021] Figure 3 c is the waveform of the current of the primary winding N1 of the coupled inductor and the current of the inductor L1;

[0022] Figure 3 d is the voltage V of diode D3 D3 And the waveform of the voltage Vc1 of capacitor C1. DETAILED DESCRIPTION

[0023] The following will be combined with the 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, not 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 are within the scope of protection of the present invention.

[0024] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0025] Specific implementation method 1. Combination Figure 1As shown, the coupled inductor square boost converter described in this embodiment includes a DC voltage source V in , diodes D0 to D4, capacitors C0 to C1, inductor L1, coupled inductor and power switch S; wherein capacitor C0 serves as an output capacitor, and the voltage across it serves as the output voltage V0 of the Boost converter;

[0026] DC voltage source V in The positive electrode of is connected to the anode of the diode D3 and the same-name end of the primary winding N1 of the coupled inductor at the same time, the opposite-name end of the primary winding N1 of the coupled inductor is connected to the anode of the diode D1 and the same-name end of the secondary winding N2 of the coupled inductor at the same time, the opposite-name end of the secondary winding N2 of the coupled inductor is connected to one end of the capacitor C1, the other end of the capacitor C1 is connected to the anode of the diode D4, the cathode of the diode D1 and the anode of the diode D2 at the same time, the cathode of the diode D4 is connected to the cathode of the diode D3 and one end of the inductor L1 at the same time, the other end of the inductor L1 is connected to the cathode of the diode D2, the drain of the power switch S and the anode of the diode D0 at the same time, and the cathode of the diode D0 is connected to one end of the capacitor C0 and one end of the load resistor R at the same time;

[0027] DC voltage source V in The negative electrode of is connected to the source of the power switch S and the other end of the capacitor C0 and the other end of the load resistor R at the same time.

[0028] Input power V in The independent inductor L1 is charged through the diode D3. At the same time, the input power supply V in The primary winding N1 of the coupled inductor is charged through diode D1 and diode D2, forming a parallel charge, so it is called inductance squared.

[0029] In this embodiment, the DC voltage source V in Directly connecting the primary winding N1 of the coupled inductor 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 power switch S. Even in the case of a large boost factor, the current ripple can be kept small. At the same time, due to the principle of magnetic induction, the voltage of the secondary winding N2 of the coupled inductor increases to charge the capacitor C1. When discharging, the capacitor C1 avoids the instability of the inductor voltage due to the discontinuous current, which in turn causes the DC link voltage to drop and other instabilities, thereby causing the output waveform to be distorted.

[0030] In addition, the voltage of the diode D3 is much lower than the output voltage, and the current of the primary winding N1 of the inductor L1 and the coupled inductor does not fluctuate greatly, which reduces energy loss, reduces component voltage stress, and reduces circuit current ripple. At the same time, it meets the requirements of fast transient response and adjusts the circuit duty cycle to optimize performance, thereby improving energy conversion efficiency and boost capability.

[0031] The coupled inductor square boost converter has the feature that the external circuit can still maintain a high voltage gain during the direct-pass stage.

[0032] Specifically, the capacitor C0, the diode D0 and the load resistor R constitute an output unit of the coupled inductor square Boost converter.

[0033] Furthermore, the voltage gain of the Boost converter Wherein, D is the on-duty cycle of the power switch S, and n1 is the turns ratio of the secondary winding N2 to the primary winding N1 of the coupled inductor. In specific applications, the on-duty cycle adjustment range of the power switch tube S is (0,1), which is adjustable within the range, and in specific applications, the optimal on-duty cycle of the power switch tube S is 0.4.

[0034] In this preferred embodiment, the voltage gain configuration can achieve the advantages of a wide adjustable range, small component voltage stress, and large voltage gain.

[0035] The coupled inductor square boost converter has two operating modes in one switching cycle, namely, an on state and an off state. Specifically,

[0036] See also Figure 2 a. In the on-state working mode, the power switch tube S is turned on, and the DC voltage source V in The inductor L1 is charged through the diode D3, and the DC voltage source V in The primary winding N1 of the coupled inductor is charged. Due to the principle of magnetic induction, the secondary winding N2 of the coupled inductor charges the capacitor C1, and the diode D1 is forward-biased and turned on. At the same time, the diodes D4 and D0 are reverse-biased and cut off, the diodes D2 and D3 are forward-biased and turned on, and the capacitor C0 supplies power to the load resistor R.

[0037] See also Figure 2 b. In the off-state working mode, the power switch tube S remains off, diodes D1 to D3 are reverse-biased and cut off, D4 is forward-biased and turned on, and capacitor C1 is discharged. At the same time, inductor L1 and the primary winding N1 of the coupled inductor and its secondary winding N2 supply power to the load resistor R and capacitor C0 through diode D0.

[0038] In the preferred embodiment, the working mode is divided into an on state and an off state, which optimizes the voltage distribution, avoids the situation where the components are always at a high voltage, and improves the energy transfer efficiency.

[0039] Verification test:

[0040] Figure 3 Given the input voltage V in =50V, output voltage V o = Experimental waveform when 283V; n1 = 2, D = 0.4, load resistance R = 200Ω. Figure 3 a is the input voltage V in =50V and output voltage V0 = 283V. Figure 3 b is the voltage V of the output diode D0 D0 The peak value is about 283V and the voltage V of the switching diode S S The peak value of the waveform is about 283V. Figure 3 c is the waveform of the primary winding N1 current and the inductor L1 current of the coupled inductor. Figure 3 d is the voltage V of diode D3 D3 And the waveform of the voltage Vc1 of capacitor C1.

[0041] from Figure 3 It can be seen from a that the voltage gain of the present invention is large, Figure 3 d can be concluded that the component voltage stress is low, Figure 3 c shows that the current ripple is small, thus verifying the technical effect of the present invention.

[0042] 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 features described in conjunction with individual embodiments may be used in other described embodiments.

Claims

1. A coupled inductor square boost converter, characterized in that: Including DC voltage source V in , diodes D0 to D4, capacitors C0 to C1, inductor L1, coupled inductor and power switch S; Wherein, capacitor C0 is used as an output capacitor, and the voltage across it is used as the output voltage V0 of the Boost converter; DC voltage source V in The positive electrode of is connected to the anode of the diode D3 and the same-name end of the primary winding N1 of the coupled inductor at the same time, the opposite-name end of the primary winding N1 of the coupled inductor is connected to the anode of the diode D1 and the same-name end of the secondary winding N2 of the coupled inductor at the same time, the opposite-name end of the secondary winding N2 of the coupled inductor is connected to one end of the capacitor C1, the other end of the capacitor C1 is connected to the anode of the diode D4, the cathode of the diode D1 and the anode of the diode D2 at the same time, the cathode of the diode D4 is connected to the cathode of the diode D3 and one end of the inductor L1 at the same time, the other end of the inductor L1 is connected to the cathode of the diode D2, the drain of the power switch S and the anode of the diode D0 at the same time, and the cathode of the diode D0 is connected to one end of the capacitor C0 and one end of the load resistor R at the same time; DC voltage source V in The negative electrode of is connected to the source of the power switch S and the other end of the capacitor C0 and the other end of the load resistor R at the same time.

2. The coupled inductor square boost converter according to claim 1, characterized in that: Voltage Gain of Boost Converter Wherein, D is the on-duty cycle of the power switch S, and n1 is the turns ratio of the secondary winding N2 to the primary winding N1 of the coupled inductor.

3. The coupled inductor square boost converter according to claim 1, characterized in that: The Boost converter has two operating modes in one switching cycle, namely the on state and the off state.

4. The coupled inductor square boost converter according to claim 3, characterized in that: In the on-state operating mode, the power switch tube S is turned on and the DC voltage source V in The inductor L1 is charged through the diode D3, and the DC voltage source V in The primary winding N1 of the coupled inductor is charged. Due to the principle of magnetic induction, the secondary winding N2 of the coupled inductor charges the capacitor C1, and the diode D1 is forward-biased and turned on. At the same time, the diodes D4 and D0 are reverse-biased and cut off, the diodes D2 and D3 are forward-biased and turned on, and the capacitor C0 supplies power to the load resistor R.

5. The coupled inductor square boost converter according to claim 3, characterized in that: In the shutdown working mode, the power switch tube S remains off, the diodes D1 to D3 are reverse biased and cut off, D4 is forward biased and turned on, and the capacitor C1 is discharged. At the same time, the inductor L1 and the primary winding N1 of the coupled inductor and its secondary winding N2 supply power to the load resistor R and the capacitor C0 through the diode D0.

6. The coupled inductor square boost converter according to claim 1, characterized in that: The on-duty cycle adjustment range of the power switch tube S is (0,1).

7. The coupled inductor square boost converter according to claim 1, characterized in that: The optimal conduction duty cycle of the power switch tube S is 0.4.

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