Non-resonant soft switching boost converter topology

Abstract

The invention discloses a non-resonant soft switching boost converter topology, and belongs to the technical field of converters. Comprising a switching tube, a boost inductor, an auxiliary inductor, a clamping capacitor, a filter capacitor, a clamping diode and a boost diode. According to the invention, the soft switch-on of the switch tube, the clamping diode and the boost diode and the soft switch-off of the clamping diode and the boost diode can be realized. Compared with an existing traditional soft switching converter, an active switching device does not need to be additionally arranged, the converter is suitable for PWM control, and the electric energy conversion efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of converters, and in particular to a non-resonant soft-switching boost converter topology. Background Art

[0002] Photovoltaic power generation is the most representative industry in the field of renewable energy power generation. It has the advantages of both distributed and centralized types. Among them, indoor DC power supply systems and photovoltaic storage and charging DC microgrids are the most typical representatives. Boost converters play an important role in photovoltaic power generation systems. Traditional boost converters are a type of hard-switching converters. Power semiconductor devices working in a hard-switching state will generate electromagnetic interference (EMI), affecting the reliability of the equipment. In addition, when used in high-frequency applications, hard-switching converters will produce greater switching losses and reduce the efficiency of power conversion. Summary of the invention

[0003] In view of the defects of the prior art, the present invention provides a non-resonant soft-switching boost converter topology, which aims to solve the high hard-switching losses of traditional buck converters and the EMI problem caused by hard switching, thereby improving the power conversion efficiency of the power devices of the entire system and the system stability.

[0004] In order to achieve the above object, the present invention provides a non-resonant soft switching boost converter topology, including: a switch tube S, a boost inductor L2, an auxiliary inductor L1, a clamping capacitor C1, a filter capacitor C2, a boost diode D1, a clamping diode D2, a first junction capacitor C D1 , the second junction capacitance C D2 ;

[0005] The first end of the boost inductor L2 is connected to the DC input power supply V in The positive electrode of the clamp diode D2 is connected, and the second end thereof is connected to the drain of the switch tube S and the first end of the auxiliary inductor L1; the second end of the auxiliary inductor L1 is connected to the first end of the clamp capacitor C1; the second end of the clamp capacitor C1 is connected to the cathode of the clamp diode D2, the anode of the boost diode D1, and the first junction capacitor C D1 The first end and the second junction capacitance C D2 The cathode of the boost diode D1 is connected to the first junction capacitor C D1 The second end of the filter capacitor C2 is connected to form an output voltage V o1 The positive end of the filter capacitor C2 and the anode of the clamping diode D2, the second junction capacitor C D2 The first end of the switch tube S, the source of the DC input power supply V in The negative connection forms the output voltage V o1 The negative terminal.

[0006] Furthermore, the DC input power supply V in Connected in series with the boost inductor L2 and the switch tube S in sequence to form a first closed loop;

[0007] The clamping diode D2 is sequentially connected in series with the clamping capacitor C1, the auxiliary inductor L1, and the switch tube S to form a second closed loop;

[0008] The filter capacitor C2 is connected in series with the output load R1 in sequence to form a third closed loop;

[0009] The DC input power supply V in It is sequentially connected in series with the boost inductor L2, the auxiliary inductor L1, the clamping capacitor C1, the boost diode D1, and the filter capacitor C2 to form a first freewheeling loop;

[0010] The DC input power supply V in The second freewheeling loop is sequentially connected in series with the boost inductor L2, the auxiliary inductor L1, the clamping capacitor C1, the boost diode D1, and the output load R1.

[0011] Furthermore, the switch tube S is a MOSFET or an IGBT.

[0012] Furthermore, the input power supply V in For all power supplies with DC output function.

[0013] Furthermore, the clamping capacitor C1 and the filter capacitor C2 are both film capacitors.

[0014] Furthermore, the first junction capacitance C D1 is the external parallel capacitor or the junction capacitance of the boost diode D1 itself; the second junction capacitance C D2 It is the external parallel capacitor or the junction capacitance of the clamping diode D2 itself.

[0015] Beneficial effects of the present invention:

[0016] 1. The present invention can realize soft switch on, soft switch on and off of clamp diode and boost diode. Compared with the PFM control mode of the traditional resonant soft switch converter, the converter provided by the present invention can be applied to the PWM control mode, which simplifies the design of the filter unit.

[0017] 2. The present invention does not require additional active switching devices to achieve soft switching, thus saving device costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the topology of a non-resonant soft-switching boost converter according to an embodiment of the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. The described embodiments should not be regarded as limiting the present application, and all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] In the following description, reference is made to “some embodiments”, “one or more embodiments”, which describe a subset of all possible embodiments, but it can be understood that “some embodiments”, “one or more embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0021] In the following description, the terms "first\second\third" are only used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged with a specific order or sequence where permitted, so that the embodiments of the present application described here can be implemented in an order other than that shown or described.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0023] like Figure 1 As shown, the embodiment of the present invention provides a non-resonant soft-switching boost converter topology, including: a DC input power supply V in , switch tube S, boost inductor L2, auxiliary inductor L1, clamp capacitor C1, filter capacitor C2, clamp diode D2, boost diode D1, first junction capacitor C D1 , the second junction capacitance C D2 .

[0024] In the embodiment of the present invention, the DC input power supply V in It can be any power supply with DC output function.

[0025] In this topology, the first end of the boost inductor L2 is connected to the DC input power supply V in The positive electrode of the clamp diode D2 is connected, and the second end thereof is connected to the drain of the switch tube S and the first end of the auxiliary inductor L1; the second end of the auxiliary inductor L1 is connected to the first end of the clamp capacitor C1; the second end of the clamp capacitor C1 is connected to the cathode of the clamp diode D2, the anode of the boost diode D1, and the first junction capacitor C D1 The first end and the second junction capacitance C D2 The cathode of the boost diode D1 is connected to the first junction capacitor C D1The second end of the filter capacitor C2 is connected to form an output voltage V o1 The positive end of the filter capacitor C2 and the anode of the clamping diode D2, the second junction capacitor C D2 The first end of the switch tube S, the source of the DC input power supply V in The negative connection forms the output voltage V o1 The negative terminal.

[0026] DC input power supply V in It is sequentially connected in series with the boost inductor L2 and the switch tube S to form a first closed loop.

[0027] The clamping diode D2 is connected in series with the clamping capacitor C1 , the auxiliary inductor L1 , and the switch tube S in sequence to form a second closed loop.

[0028] The filter capacitor C2 is sequentially connected in series with the output load R1 to form a third closed loop.

[0029] DC input power supply V in The first freewheeling loop is sequentially connected in series with the boost inductor L2, the auxiliary inductor L1, the clamping capacitor C1, the boost diode D1, and the filter capacitor C2.

[0030] DC input power supply V in The second freewheeling loop is sequentially connected in series with the boost inductor L2, the auxiliary inductor L1, the clamping capacitor C1, the boost diode D1, and the output load R1.

[0031] The first junction capacitance C D1 It can be an external parallel capacitor or the junction capacitance of the boost diode D1 itself; the second junction capacitance C D2 It can be an external parallel capacitor or the junction capacitance of the clamping diode D2 itself.

[0032] In order to more clearly explain the embodiment of the present invention, the principle of the present invention is described in detail below. Considering that the capacitance of the clamping capacitor C1 and the filter capacitor C2 is large enough, ignoring the ripple and approximating the constant voltage, non-polar film capacitors can be used in practice. The inductance of the boost inductor L2 is large enough to be connected to the DC input power supply V in The series connection is equivalent to a constant current source. The switch tube S is a metal oxide semiconductor field effect transistor (MOSFET) tube or an insulated gate bipolar transistor (IGBT).

[0033] Before the switch tube S is turned on, the clamping diode D2 is turned off, the boost diode D1 is turned on, and i D1 =i L1 When the switch tube S is turned on, the auxiliary inductor L1 limits the current i of the switch tube S. SLinear rise speed, so the switch tube S is turned on with zero current. Similarly, the current i of the switch tube S is S The current i of the auxiliary inductor L1 rises linearly. L1 Linearly decreases, so the boost diode D1 is turned off with zero current. At this time, the boost diode D1 is cut off and the clamping diode D2 is turned on. Also, due to the existence of the auxiliary inductor L1, the current i of the clamping diode D2 is limited. D2 The speed of linear rise is such that the clamping diode D2 is turned on with zero current.

[0034] Before the switch S is turned off, the current i of the clamping diode D2 D2 The current of the switch tube S naturally drops to zero, so the clamping diode D2 is turned off with zero current, and the boost diode D1 is cut off at this time. When the switch tube S is turned off, due to the existence of the auxiliary inductor L1, the current i S Linearly decreases, the clamping diode D2 is cut off, and the boost diode D1 is turned on, so the current i of the boost diode D1 is D1 It rises linearly, limiting the current rising speed, and the boost diode D1 is turned on at zero current.

[0035] The embodiment of the present invention utilizes the auxiliary inductor L1 to realize the soft turning on of the switch tube S and the soft turning off and turning on of all diodes. In addition, the defect that the filter unit of the quasi-resonant PFM quasi-resonant converter is difficult to design and the limitation that the ZVT / ZCT PWM converter needs to add additional active switching devices are optimized. Thus, the overall cost of the converter is saved and the control strategy is simplified.

[0036] The above is only an embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement and improvement made within the spirit and scope of the present application are included in the protection scope of the present application.

Claims

1. A non-resonant soft-switching boost converter topology, characterized in that: include: Switch tube S, boost inductor L2, auxiliary inductor L1, clamp capacitor C1, filter capacitor C2, boost diode D1, clamp diode D2, first junction capacitor C D1 , the second junction capacitance C D2 The first end of the boost inductor L2 is connected to the DC input power supply V in The positive electrode of the clamp diode D2 is connected, and the second end thereof is connected to the drain of the switch tube S and the first end of the auxiliary inductor L1; the second end of the auxiliary inductor L1 is connected to the first end of the clamp capacitor C1; the second end of the clamp capacitor C1 is connected to the cathode of the clamp diode D2, the anode of the boost diode D1, and the first junction capacitor C D1 The first end and the second junction capacitance C D2 The cathode of the boost diode D1 is connected to the first junction capacitor C D1 The second end of the filter capacitor C2 is connected to form an output voltage V o1 The positive end of the filter capacitor C2 and the anode of the clamping diode D2, the second junction capacitor C D2 The first end of the switch tube S, the source of the DC input power supply V in The negative connection forms the output voltage V o1 The negative terminal.

2. The non-resonant soft-switching boost converter topology according to claim 1, characterized in that: The DC input power supply V in Connected in series with the boost inductor L2 and the switch tube S in sequence to form a first closed loop; The clamping diode D2 is sequentially connected in series with the clamping capacitor C1, the auxiliary inductor L1, and the switch tube S to form a second closed loop; The filter capacitor C2 is connected in series with the output load R1 in sequence to form a third closed loop; The DC input power supply V in It is sequentially connected in series with the boost inductor L2, the auxiliary inductor L1, the clamping capacitor C1, the boost diode D1, and the filter capacitor C2 to form a first freewheeling loop; The DC input power supply V in The second freewheeling loop is sequentially connected in series with the boost inductor L2, the auxiliary inductor L1, the clamping capacitor C1, the boost diode D1, and the output load R1.

3. The non-resonant soft-switching boost converter topology according to claim 1, characterized in that: The switch tube S is a MOSFET or an IGBT.

4. The non-resonant soft-switching boost converter topology according to claim 1, characterized in that: The input power supply V in For all power supplies with DC output function.

5. The non-resonant soft-switching boost converter topology according to claim 1, characterized in that: The clamping capacitor C1 and the filter capacitor C2 are both film capacitors.

6. The non-resonant soft-switching boost converter topology according to claim 1, characterized in that: The first junction capacitance C D1 is the external parallel capacitor or the junction capacitance of the boost diode D1 itself; the second junction capacitance C D2 It is the external parallel capacitor or the junction capacitance of the clamping diode D2 itself.

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