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

Abstract

The invention discloses a high-boost single-switch bridgeless rectification circuit for a low-voltage input source, and relates to the technical field of converters. The high-boost single-switch bridgeless rectification circuit comprises an inductor L1, an inductor L2, an inductor LS, a switch tube S, a diode D1, a diode D2, a diode DS1, a diode DS2, a diode DR1, a diode DR2, an output diode Do, an output capacitor Co and an intermediate capacitor Cm. The inductor L1, the diode D1 and the diode DS1 form a secondary boosting unit which is used for electric energy conversion in an alternating current positive input period; the inductor L2, the diode D2 and the diode DS2 form another secondary boosting unit which is used for electric energy conversion in the alternating current negative input period; according to the high-boost single-switch bridgeless rectification circuit, only one switch MOSFET tube is used, so that the voltage and power loss is reduced, and the overall efficiency of the conversion circuit is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of converters, and in particular 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 more and more popular in today's reality. In order to realize the layout of the Internet of Things, there are now solutions that use energy recovery devices to collect environmental energy into power electronic devices for energy storage to help wireless sensor nodes (WSNs) feedback signals. However, energy recovery devices usually only provide very low AC output voltages. How to provide stable and efficient input voltages for wireless sensors is an urgent problem to be solved.

[0003] The existing power supply scheme based on environmental micro-energy mainly generates low-voltage AC output voltage (such as 1V) through a small power generation device, and then achieves a stable low-voltage (such as 9V) output through an AC-DC conversion circuit to power the subsequent battery pack and load. However, this type of scheme has the following problems, which is not conducive to efficient energy conversion.

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

[0005] 2) Traditional bridgeless conversion circuits usually use multiple MOSFET switches, which causes unnecessary energy loss.

[0006] The present invention proposes a high-boost single-switch bridgeless rectifier circuit for low-voltage input sources, 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 can reduce the voltage and power losses in traditional converter circuits. Summary of the invention

[0007] The purpose of the present invention is to provide a high-voltage boost single-switch bridgeless rectifier circuit for a low-voltage input source to solve the problems in the prior art mentioned in the above background technology that the converter circuit cannot efficiently convert the low-voltage AC input of a low-voltage generator.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] A high boost single switch bridgeless rectifier circuit for low voltage input source, including 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 and the intermediate capacitor C m ;

[0010] The inductor L1, the diode D1, the diode D S1 A secondary boost unit is formed for power conversion in the positive input cycle of AC;

[0011] The inductor L2, the diode D2, the diode D S2 Another secondary boost unit is formed for power conversion during the negative input cycle of AC;

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

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

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

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

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

[0017] Preferably, the operating mode of the high boost single switch bridgeless rectifier circuit during the AC positive input cycle is as follows:

[0018] Working mode 1: When the switch tube S is closed, the input end passes through the diode DS1 The switch tube S charges the inductor L1, and the intermediate capacitor C m Through the switch tube S to the inductor L S Charging, while the output capacitor C o Supply power to the load; during this period, the inductor L1 and the inductor L S The current i L1 and current i LS Increase linearly;

[0019] Working mode 2: When the switch tube S is turned off, the energy input and stored in the inductor L1 is given to the intermediate capacitor C m In addition, the input and the energy stored in the inductor L1 and the inductor L S The energy in the o Give the 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;

[0020] Working mode 3: switch tube S is in the off state; current i L1 and current i LS Keep it at zero, the output capacitor C o Supply power to the load.

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

[0022] Working mode 4: When the switch tube S is closed, the input end passes through the diode D S2 The switch tube S charges the inductor L2, and the intermediate capacitor C m Through the switch tube S to the inductor L S Charging, while the output capacitor C o Supply power to the load; during this period, the inductor L2 and the inductor L S The current i L2 and current i LS Increase linearly;

[0023] Working mode 5: When the switch tube S is turned off, the energy input and stored in the inductor L2 is given to the intermediate capacitor C m In addition, the input and the energy stored in the inductor L2 and the inductor L S The energy in the o Give the output capacitor C o and load power supply; during this period, the current i L2 and current i LSIt 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;

[0024] Working mode 6: switch tube S is in the off state; current i L2 and current i LS Keep it at zero, the output capacitor C o Supply power to the load.

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

[0026] Output voltage V o Sampling signal and output reference voltage V o,ref The error feedback signal is compared with the triangular wave to generate the driving signal G of the switch tube S. S .

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) Compared with most existing bridgeless converters, the high-boost single-switch bridgeless rectifier circuit of the present invention uses only one switching MOSFET tube, which reduces voltage and power losses and improves the overall efficiency of the conversion circuit.

[0029] (2) The high-voltage single-switch bridgeless rectifier circuit of the present invention has a simple structure, a small number of components, low cost, and a small size, and is suitable for wireless data sampling application scenarios based on weak power recovery input and requiring high voltage output. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a topological diagram of a conventional quadratic boost converter;

[0031] Figure 2 A topological schematic diagram of a high-voltage boost single-switch bridgeless rectifier circuit in the present invention;

[0032] Figure 3 Schematic diagram of equivalent working mode of the high boost single switch bridgeless rectifier circuit in the present invention;

[0033] Figure 4 It is a key waveform diagram of the components of the high-voltage boost single-switch bridgeless rectifier circuit in the present invention;

[0034] Figure 5 It is a control implementation principle diagram of the high boost single switch bridgeless rectifier circuit in the present invention;

[0035] Figure 6 This is a waveform simulation diagram of key components of the high-voltage boost single-switch bridgeless rectifier circuit in the present invention. DETAILED DESCRIPTION

[0036] 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.

[0037] Embodiment 1:

[0038] Figure 1 The quadratic boost unit used in the conventional quadratic boost converter circuit can be regarded as a cascade boost topology. This topology uses a diode to avoid the two MOSFETs required when the two boost units are cascaded. The quadratic boost unit can achieve high voltage boost. Therefore, the present invention proposes a bridgeless converter using only one MOSFET based on the boost unit, and eliminates the need for a cascaded MOSFET. Figure 1 The rectifier diode on the input side reduces the conduction voltage drop of the rectifier bridge diode.

[0039] The present invention connects the input and output of the secondary boost unit in parallel, and then simplifies the topology to obtain the following: Figure 2 The quadratic high boost single switch circuit shown can realize operation in positive and negative AC input cycles through two parallel quadratic conversion units.

[0040] The circuit of the present invention mainly includes an inductor L1, an inductor L2, an 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 the inductor L1 is connected to one end of the input terminal, and the diode D R1 The cathode of the inductor L1 is connected to the other end of the diode D S1 The anode of the diode D1 is connected; one end of the inductor L2 is connected to the other end of the input end, and the diode D R2 The cathode of the inductor L2 is connected to the other end of the diode D S2 The anode of the diode D2 is connected; the inductor L S One end is connected to the cathode of diode D1, the cathode of diode D2, and the intermediate capacitor C m The positive pole is connected to the inductor L SThe other end is connected to the drain of the switch tube S and the diode D S1 The cathode of diode D S2 The cathode of the output diode D o The output capacitor C o The positive electrode of the output diode D o The cathode and load are connected, and the output capacitor C o The negative electrode of the switch tube S and the source of the intermediate capacitor C m The cathode of diode D R1 The anode of diode D R2 The anode of the load is connected to the other end.

[0042] Since the working modes of the converter in the positive and negative input cycles of AC 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 AC, such 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 operating mode 3 of the high boost single switch bridgeless rectifier circuit.

[0044] Depend on Figure 3 The working mode of the device can obtain the key device waveform, Figure 4 This is a key waveform diagram of the high-voltage boost bridgeless rectifier circuit device of the present invention.

[0045] Working mode 1: When the switch tube S is closed, the input end passes through the diode D S1 The switch tube S charges the inductor L1, and the intermediate capacitor C m Through the switch tube S to the inductor L S Charging, while the output capacitor C o During this period, the inductor L1 and the inductor L S The current i L1 and current i LS Increases linearly.

[0046] Working mode 2: When the switch tube S is turned off, the energy input and stored in the inductor L1 is given to the intermediate capacitor C m In addition, the input and the stored inductor L1 and inductor L S The energy in the o Give the 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.L1 and current i LS When it drops to 0, the next working mode begins.

[0047] Working mode 3: The switch tube S is in the off state. Current i L1 and i LS Keep it at zero. Output capacitor C o Supply power to the load.

[0048] The discontinuous conduction mode (DCM) operation mode of the high boost single switch bridgeless rectifier circuit during the AC negative input cycle is as follows:

[0049] Working mode 4: When the switch tube S is closed, the input end passes through the diode D S2 The switch tube S charges the inductor L2, and the intermediate capacitor C m Through the switch tube S to the inductor L S Charging, while the output capacitor C o During this period, the inductor L2 and the inductor L S The current i L2 and current i LS Increases linearly.

[0050] Working mode 5: When the switch tube S is turned off, the energy input and stored in the inductor L2 is given to the intermediate capacitor C m In addition, the input and the stored inductor L2 and inductor L S The energy in the o Give the 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. L2 and current i LS When it drops to 0, the next working mode begins.

[0051] Working mode 6: The switch tube S is in the off state. Current i L2 and current i LS Keep it at zero. Output capacitor C o Supply power to the load.

[0052] The specific control method of the high boost single switch bridgeless rectifier circuit in the present invention is as follows: Figure 5 As shown. Output voltage V o Sampling signal and output reference voltage V o,ref The error feedback signal is compared with the triangular wave to generate the driving signal G of the switch tube S. S .

[0053] Experimental verification:

[0054] In order 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: AC input adopts sinusoidal signal fitting, AC voltage peak is 1.2V, frequency is 300Hz, inductance L1, inductance L2 are 1.5uH, energy storage inductance L S is 4.8uH, output capacitor C o is 100uF, the middle capacitor C m The resistor is 200uF, the output voltage is 9V, the load resistance is 300Ω, the switching frequency is 47kHZ, and the P and I parameters in PI are 0.8 and 0.005.

[0055] Figure 6 The waveform simulation diagram of the key components of the bridgeless boost converter is shown in Figure 2. It can be seen that the inductor L1 and the inductor L2 only work in each AC input cycle, realizing the bridgeless working mode of the converter. In addition, the input voltage V in First, pressurize V cm (through the middle capacitor C m The voltage across the two ends of the voltage is stabilized 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 inductors L1, L2 and L S Both work in DCM mode, and the simulation results are consistent with Figure 4 The theoretical waveform is basically consistent, which verifies the correctness of the theoretical analysis and the effectiveness of the topology of the present invention.

[0056] The above description is only used to help understand the method of the present invention and its core essence, but the protection scope of the present invention is not limited thereto. For those skilled in the art in the art, equivalent replacement or change according to the technical solution and inventive concept of the present invention within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A high boost single switch bridgeless rectifier circuit for low voltage input source, characterized in that: Including 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 and the intermediate capacitor C m ; The inductor L1, the diode D1, the diode D S1 A secondary boost unit is formed for power conversion in the positive input cycle of AC; The inductor L2, the diode D2, the 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 booster units are connected in parallel and the outputs are connected in parallel.

2. The high boost single switch bridgeless rectifier circuit for low voltage input source according to claim 1, characterized in that: One end of the input terminal is connected to the diode D R1 The cathode of the diode D1 is connected to one end of the inductor L1, and the other end of the inductor L1 is connected to the anode of the diode D1 and the S1 The anode of is connected; The other end of the input terminal is connected to the diode D R2 The cathode of the diode D2 is connected to one end of the inductor L2, and the other end of the inductor L2 is connected to the anode of the diode D2. S2 The anode of is connected; Intermediate capacitor C m The positive electrode of the diode D1, the cathode of the diode D2, and the inductor L S One end of the inductor is connected to S The other end of the diode D S1 The cathode of diode D S2 The cathode of the switch tube S, the drain of the output diode D o The anode of the output diode 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 The anode of diode D R2 The anode of the switch tube S, the source of the output capacitor C o The negative pole of the load is connected to the other end.

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 positive input cycle is as follows: Working mode 1: When the switch tube S is closed, the input end passes through the diode D S1 The switch tube S charges the inductor L1, and the intermediate capacitor C m Through the switch tube S to the inductor L S Charging, while the output capacitor C o Supply power to the load; during this period, the inductor L1 and the inductor L S The current i L1 and current i LS Increase linearly; Working mode 2: When the switch tube S is turned off, the energy input and stored in the inductor L1 is given to the intermediate capacitor C m In addition, the input and the energy stored in the inductor L1 and the inductor L S The energy in the o Give the 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 is in the off state; current i L1 and current i LS Keep it at zero, the output capacitor C o Supply power to the load.

4. The high boost single switch bridgeless rectifier circuit for low voltage input source according to claim 3, characterized in that: The working mode during the AC negative input cycle is as follows: Working mode 4: When the switch tube S is closed, the input end passes through the diode D S2 The switch tube S charges the inductor L2, and the intermediate capacitor C m Through the switch tube S to the inductor L S Charging, while the output capacitor C o Supply power to the load; during this period, the inductor L2 and the inductor L S The current i L2 and current i LS Increase linearly; Working mode 5: When the switch tube S is turned off, the energy input and stored in the inductor L2 is given to the intermediate capacitor C m In addition, the input and the energy stored in the inductor L2 and the inductor L S The energy in the o Give the 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 is in the off state; current i L2 and current i LS Keep it at zero, the output capacitor C o Supply power to the load.

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

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