High-boost single-switch bridgeless rectifier circuit for low-voltage input source

Abstract

The present invention discloses a high-boost single-switch bridgeless rectifier circuit for a low-voltage input source, which relates to the technical field of converters; the high-boost single-switch bridgeless rectifier circuit includes an inductor L1, an inductor L2, an inductor L S , a switch tube S, a diode D1, a diode D2, a diode D S1 , a diode D S2 , a diode D R1 , a diode D R2 , an output diode D o , an output capacitor C o , and an intermediate capacitor C m ; the inductor L1, the diode D1, and the diode D S1 form a quadratic boost unit for power conversion during the positive half-cycle of the AC input; the inductor L2, the diode D2, and the diode D S2 form another quadratic boost unit for power conversion during the negative half-cycle of the AC input; in the high-boost single-switch bridgeless rectifier circuit of the present invention, only one switch MOSFET tube is used, reducing voltage and power losses and improving the overall efficiency of the conversion circuit.

Description

Technical Field

[0001] The present invention belongs to the technical field of converters, and particularly relates to a high-boost single-switch bridgeless rectifier circuit for a low-voltage input source. Background Art

[0002] With the development of computing power and the maturity of technology, artificial intelligence models, sensor technology, and the Internet of Things (IoT) are becoming increasingly popular in today's reality. To implement the layout of the Internet of Things, there is currently a solution to collect environmental energy into power electronic devices through an energy recovery device for energy storage to help wireless sensor nodes (WSNs) feedback signals. However, the energy recovery device usually only provides a very low AC output voltage, and how to provide a stable and efficient input voltage for wireless sensors is an urgent problem to be solved.

[0003] In the existing solution for power supply based on ambient micro-energy, a small power generation device is mainly used to generate a low-voltage alternating current (AC) output voltage (such as 1V), and then a stable low voltage (such as 9V) output is achieved through an AC-DC power conversion circuit to supply power to the subsequent battery pack and load. However, this type of solution has the following problems and is not conducive to efficient energy conversion.

[0004] 1) The traditional converter circuit uses a bridge rectifier. In an actual circuit, due to the existence of the diode conduction voltage drop and conduction loss, it is easy to cause voltage and power loss in the converter circuit.

[0005] 2) The traditional bridgeless conversion circuit usually uses multiple MOSFET switches, which causes redundant energy loss.

[0006] The present invention proposes a high-boost single-switch bridgeless rectifier circuit for a low-voltage input source, which can solve the problem that the low-voltage AC input of a low-voltage power generation device cannot be efficiently converted, and by using only one switching MOSFET tube, it is possible to reduce the voltage and power loss in the traditional converter circuit. Summary of the Invention

[0007] The purpose of the present invention is to provide a high-boost single-switch bridgeless rectifier circuit for a low-voltage input source to solve the problems such as the inefficient conversion of the low-voltage AC input of the converter circuit in the prior art as mentioned in the above background art.

[0008] To achieve the above purpose, the present invention is implemented by adopting the following technical solutions:

[0009] A high-boost single-switch bridgeless rectifier circuit for a low-voltage input source includes an inductor L1, an inductor L2, an inductor L S , a switch tube S, a diode D1, a diode D2, a diode D S1 , a diode D S2, Diode D R1 , Diode D R2 , Output Diode D o , Output Capacitor C o and Intermediate Capacitor C m ;

[0010] The inductor L1, diode D1, and diode D S1 form a quadratic boost unit for power conversion during the positive half-cycle of the AC input;

[0011] The inductor L2, diode D2, and diode D S2 form another quadratic boost unit for power conversion during the negative half-cycle of the AC input;

[0012] The inputs of the two quadratic boost units are connected in parallel and the outputs are connected in parallel.

[0013] Preferably, one end of the input terminal is connected to the cathode of diode D R1 and one end of inductor L1. The other end of inductor L1 is connected to the anode of diode D1 and the anode of diode D S1 ;

[0014] The other end of the input terminal is connected to the cathode of diode D R2 and one end of inductor L2. The other end of inductor L2 is connected to the anode of diode D2 and the anode of diode D S2 ;

[0015] The positive electrode of the intermediate capacitor C m is connected to the cathodes of diode D1, diode D2, and one end of inductor L S . The other end of inductor L S is connected to the cathode of diode D S1 , the cathode of diode D S2 , the drain of switch S, and the anode of output diode D o . The cathode of output diode D o is connected to the positive electrode of output capacitor C o and one end of the load;

[0016] The negative electrode of the intermediate capacitor C m is connected to the anode of diode D R1 , the anode of diode D R2 , the source of switch S, the negative electrode of output capacitor C o and the other end of the load.

[0017] Preferably, the operating modes during the positive half-cycle of the AC input of the high-boost single-switch bridgeless rectifier circuit are as follows:

[0018] Operating Mode 1: When switch S is closed, the input terminal passes through diode DS1 The switch tube S and the inductor L1 are used to charge the intermediate capacitor C m The switch tube S is used to charge the inductor L S while the output capacitor C o supplies power to the load; during this period, the currents i S in the inductor L1 and the inductor L L1 and the current i LS increase linearly;

[0019] Operating mode 2: When the switch tube S is turned off, the input and the energy stored in the inductor L1 are used to charge the intermediate capacitor C m In addition, the input and the energy stored in the inductor L1 and the inductor L S are used to supply power to the output capacitor C o through the output diode D o while the currents i L1 and the current i LS decrease linearly until approaching zero; when the currents i L1 and the current i LS drop to 0, the next operating mode starts;

[0020] Operating mode 3: The switch tube S is in the off state; the currents i L1 and the current i LS remain zero, and the output capacitor C o supplies power to the load.

[0021] Preferably, the operating modes during the AC negative input cycle of the high-boost single-switch bridgeless rectifier circuit are as follows:

[0022] Operating mode 4: When the switch tube S is closed, the input terminal charges the inductor L2 through the diode D S2 and the switch tube S, and the intermediate capacitor C m charges the inductor L S through the switch tube S while the output capacitor C o supplies power to the load; during this period, the currents i S in the inductor L2 and the inductor L L2 and the current i LS increase linearly;

[0023] Operating mode 5: When the switch tube S is turned off, the input and the energy stored in the inductor L2 are used to charge the intermediate capacitor C m In addition, the input and the energy stored in the inductor L2 and the inductor L S are used to supply power to the output capacitor C o through the output diode D o while the currents i L2 and the current i LSIt decreases linearly until it approaches zero; when the current i L2 and the current i LS drop to 0, the next working mode starts;

[0024] Working mode 6: The switch tube S is in the off state; the current i L2 and the current i LS remain zero, and the output capacitor C o powers the load.

[0025] Preferably, the driving of the switch tube S is as follows:

[0026] The sampling signal of the output voltage V o is compared with the output reference voltage V o,ref , and then the error feedback signal is obtained through PI parameter adjustment. The error feedback signal is compared with the triangular wave to generate the driving signal G S of the switch tube S.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] (1) Compared with most existing bridge - less converters, in the present invention, the high - boost single - switch bridge - less rectifier circuit only uses one switch MOSFET tube, reducing voltage and power losses and improving the overall efficiency of the conversion circuit.

[0029] (2) The high - boost single - switch bridge - less rectifier circuit in the present invention has a simple structure, fewer devices, low cost, and small volume, and is suitable for wireless data sampling application scenarios that require high - voltage output while recovering weak electrical energy input. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a topological schematic diagram of a traditional quadratic boost converter;

[0031] Figure 2 is a topological schematic diagram of the high - boost single - switch bridge - less rectifier circuit in the present invention;

[0032] Figure 3 is an equivalent working mode schematic diagram of the high - boost single - switch bridge - less rectifier circuit in the present invention;

[0033] Figure 4 is a key waveform diagram of the devices of the high - boost single - switch bridge - less rectifier circuit in the present invention;

[0034] Figure 5 is a schematic diagram of the control implementation principle of the high - boost single - switch bridge - less rectifier circuit in the present invention;

[0035] Figure 6 is a waveform simulation diagram of the key devices of the high - boost single - switch bridge - less rectifier circuit in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0036] Next, in combination with the accompanying drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0037] Embodiment 1:

[0038] Figure 1 The quadratic boost unit used in the traditional quadratic boost converter circuit can be regarded as a cascaded boost topology. This topology uses a diode to avoid the two MOSFETs required when the original two boost units are cascaded. The quadratic boost unit can achieve high-voltage boost. Therefore, based on this boost unit, the present invention proposes a bridge-less converter that only uses one MOSFET and eliminates Figure 1 the rectifier diode on the input side, reducing the conduction voltage drop of the rectifier bridge diode.

[0039] By performing input parallel and output parallel on the quadratic boost unit and then simplifying the topology, the present invention can obtain a quadratic high-boost single-switch circuit as shown in Figure 2 which can operate in both positive and negative AC input cycles through two parallel quadratic conversion units.

[0040] The circuit of the present invention mainly includes inductor L1, inductor L2, inductor L S , switch tube S, diode D1, diode D2, diode D S1 , diode D S2 , diode D R1 , diode D R2 , output diode D o , output capacitor C o , intermediate capacitor C m .

[0041] Specifically, one end of inductor L1 is connected to one end of the input terminal and the cathode of diode D R1 , the other end of inductor L1 is connected to the anode of diode D S1 and the anode of diode D1; one end of inductor L2 is connected to the other end of the input terminal and the cathode of diode D R2 , the other end of inductor L2 is connected to the anode of diode D S2 and the anode of diode D2; one end of inductor L S is connected to the cathode of diode D1, the cathode of diode D2, and the positive electrode of intermediate capacitor C m , one end of inductor L SThe other end is connected to the drain of the switching transistor S, the cathode of the diode D S1 the cathode of the diode D S2 the cathode of the output diode D o the anode is connected; the output capacitor C o the positive electrode is connected to the output diode D o the cathode, one end of the load, the output capacitor C o the negative electrode is connected to the source of the switching transistor S, the negative electrode of the intermediate capacitor C m the negative electrode of the diode D R1 the anode of the diode D R2 the anode, the other end of the load.

[0042] Since the working modes of the converter in the positive and negative input cycles of the alternating current are similar, the present invention mainly introduces the discontinuous conduction mode (DCM) working mode of the high-boost single-switch bridgeless rectifier circuit in the positive input cycle of the alternating current, as Figure 3 shown.

[0043] Figure 3 (a) is the working mode 1 of the high-boost single-switch bridgeless rectifier circuit; Figure 3 (b) is the working mode 2 of the high-boost single-switch bridgeless rectifier circuit; Figure 3 (c) is the working mode 3 of the high-boost single-switch bridgeless rectifier circuit.

[0044] From Figure 3 the working mode, the waveforms of the key devices of the device can be obtained, Figure 4 which is the key waveform diagram of the devices of the high-boost bridgeless rectifier circuit of the present invention.

[0045] Working mode 1: When the switching transistor S is closed, the input terminal charges the inductor L1 through the diode D S1 and the switching transistor S, and the intermediate capacitor C m charges the inductor L S through the switching transistor S, and at the same time the output capacitor C o powers the load. During this period, the currents i S in the inductor L1 and the inductor L L1 and the current i LS increase linearly.

[0046] Working mode 2: When the switching transistor S is turned off, the input and the energy stored in the inductor L1 charge the intermediate capacitor C m . In addition, the input and the energy stored in the inductor L1 and the inductor L S together, through the output diode D o power the output capacitor C o and the load. During this period, the currents i L1 and the current i LS decrease linearly until approaching zero. When the current iL1 and current i LS When it drops to 0, the next operating mode starts.

[0047] Operating mode 3: The switch S is in the off state. The current i L1 and i LS remain zero. The output capacitor C o powers the load.

[0048] The discontinuous conduction mode (DCM) operating modes of the AC negative input cycle of the high-boost single-switch bridgeless rectifier circuit in the present invention are as follows:

[0049] Operating mode 4: When the switch S is closed, the input terminal charges the inductor L2 through the diode D S2 and the switch S, and the intermediate capacitor C m charges the inductor L through the switch S S , and at the same time the output capacitor C o powers the load. During this period, the currents i S in the inductor L2 and the inductor L L2 and the current i LS increase linearly.

[0050] Operating mode 5: When the switch S is opened, the input and the energy stored in the inductor L2 charge the intermediate capacitor C m . In addition, the input and the energy stored in the inductor L2 and the inductor L S together, through the output diode D o power the output capacitor C o and the load. During this period, the currents i L2 and the current i LS decrease linearly until approaching zero. When the currents i L2 and the current i LS drop to 0, the next operating mode starts.

[0051] Operating mode 6: The switch S is in the off state. The current i L2 and the current i LS remain zero. The output capacitor C o powers the load.

[0052] The specific control method of the high-boost single-switch bridgeless rectifier circuit in the present invention is as Figure 5 shown. The sampling signal of the output voltage V o is compared with the output reference voltage V o,ref , and then through PI parameter adjustment to obtain an error feedback signal, and the error feedback signal is compared with a triangular wave to generate the drive signal G S of the switch S.

[0053] Experimental verification:

[0054] To verify the feasibility of the AC-DC power conversion circuit of the present invention, the PSIM simulation software was used to simulate and verify the circuit. Specific parameters: The AC input uses a sine signal fitting, the peak value of the AC voltage is 1.2V, the frequency is 300Hz, the inductances L1 and L2 are 1.5uH, the energy storage inductance L S is 4.8uH, the output capacitor C o is 100uF, the intermediate capacitor C m is 200uF, the output voltage is 9V, the load resistance is 300Ω, the switching frequency is 47kHZ, and in the PI parameters, P is 0.8 and I is 0.005.

[0055] Figure 6 It is the waveform simulation diagram of the key devices of the bridgeless boost converter. It can be seen that the inductances L1 and L2 only work in each AC input cycle, realizing the bridgeless working mode of the converter. In addition, the input voltage V in is first applied to both ends of V cm (the voltage passing through the intermediate capacitor C m ) and stabilizes at about 1.5V. Then, it is further boosted to the output voltage V o = 9V. The results show that the converter works stably, and the inductances L1, L2, and L S all work in the DCM mode. The simulation results are basically consistent with the Figure 4 theoretical waveform, verifying the correctness of the theoretical analysis and the effectiveness of the topology of the present invention.

[0056] As described above, it is only used to help understand the method of the present invention and its core idea, but the protection scope of the present invention is not limited thereto. For those of ordinary skill in the art in the technical field disclosed by the present invention, any equivalent replacement or change made according to the technical solution and inventive concept of the present invention should be covered within the protection scope of the present invention. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A high boost single switch bridgeless rectifier circuit for low voltage input source, characterized in that: Including inductor L 1. Inductor L 2. Inductor L S , switch tube S ,diode D 1. Diode D 2. Diode D S1 ,diode D S2 ,diode D R1 ,diode D R2 , output diode D o , output capacitor C o and the intermediate capacitor C m ; The inductor L 1. Diode D 1. Diode D S1 A secondary boost unit is formed for power conversion in the positive input cycle of AC; The inductor L 2. Diode D 2. Diode D S2 Another secondary boost unit is formed for power conversion during the negative input cycle of AC; The inputs of the two quadratic boost units are connected in parallel and the outputs are connected in parallel; One end of the input terminal is connected to the diode D R1 Cathode, inductor L 1 is connected to one end, the inductor L The other end of the diode D 1 anode, diode D S1 The anode of is connected; The other end of the input terminal is connected to the diode D R2 Cathode, inductor L 2 is connected to one end, the inductor L 2 and the other end of the diode D 2 anode, diode D S2 The anode of is connected; Intermediate Capacitor C m The positive electrode of the diode D 1 cathode, diode D 2 cathode, inductor L S One end of the inductor is connected to L S The other end of the diode D S1 The cathode of the diode D S2 The cathode and switch tube S The drain and output diode D o The anode of the output diode is connected to D o The cathode and output capacitor C o The positive electrode and the load end are connected; Intermediate Capacitor C m The cathode of the diode D R1 Anode, diode D R2 Anode, switch tube S The source and output capacitors C o The negative pole of the load is connected to the other end.

2. The high boost single switch bridgeless rectifier circuit for low voltage input source according to claim 1, characterized in that: The working mode during the AC positive input cycle is as follows: Working mode 1: switch tube S When closed, the input passes through the diode D S1 And switch tube S To inductor L 1Charge, intermediate capacitor C m Through the switch S To inductor L S Charging while outputting capacitor C o Supply power to the load; during this period, the inductor L 1 and inductor L S Current in i L1 and current i LS Increase linearly; Working mode 2: switch tube S When disconnected, the input and the stored inductor L The energy in 1 is given to the middle capacitor C m charging; in addition, the input and storage in the inductor L 1 and inductor L S The energy in the D o To output capacitor C o and load power supply; during this period, the current i L1 and current i LS It decreases linearly until it approaches zero; When the current i L1 and current i LS When it drops to 0, the next working mode begins; Working mode 3: switch tube S In the off state; Current i L1 and current i LS Keep it at zero, the output capacitance C o Supply power to the load.

3. The high boost single switch bridgeless rectifier circuit for low voltage input source according to claim 2, characterized in that: The working mode during the AC negative input cycle is as follows: Working mode 4: switch tube S When closed, the input passes through the diode D S2 And switch tube S To inductor L 2Charge, intermediate capacitor C m Through the switch S To inductor L S Charging while outputting capacitor C o Supply power to the load; during this period, the inductor L 2 and inductor L S Current in i L2 and current i LS Increase linearly; Working mode 5: switch tube S When disconnected, the input and the stored inductor L The energy in 2 is given to the middle capacitor C m charging; in addition, the input and storage in the inductor L 2 and inductor L S The energy in the D o To output capacitor C o and load power supply; during this period, the current i L2 and current i LS It decreases linearly until it approaches zero; When the current i L2 and current i LS When it drops to 0, the next working mode begins; Working mode 6: switch tube S In the off state; Current i L2 and current i LS Keep it at zero, the output capacitance C o Supply power to the load.

4. The high boost single switch bridgeless rectifier circuit for low voltage input source according to claim 2 or 3, characterized in that: The switch tube S The drivers are as follows: Output voltage V o Sampling signal and output reference voltage V o,ref The error feedback signal is compared with the triangle wave to generate the switch. S The driving signal G S .

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