Bridgeless boost rectifier circuit for low voltage energy recovery source

Abstract

The invention discloses a bridgeless boost rectifier circuit for a low-voltage energy recovery source, and relates to the technical field of electric energy conversion circuits. The bridgeless boost rectifier circuit includes an inductor L 1. Inductor L 2. Switching tube S 1. Switching tube S 2. Output diode D 1. Output diode D 2. Output capacitor C o ; Switching tube S 2. Inductor L 2. Output diode D 2 forms a Buck-boost unit, Buck-boost unit and output capacitor C o Connection to achieve power conversion in the positive half cycle of AC input; switch tube S 1. Inductor L 1. Output diode D 1 constitutes the Boost unit, the Boost unit and the output capacitor C o The connection is used to realize the power conversion in the negative half cycle of the AC input. Compared with most existing bridgeless converters, the present invention completely eliminates the diode rectifier bridge, thereby improving the overall efficiency of the conversion circuit.

Description

Technical Field

[0001] The invention belongs to the technical field of electric energy conversion circuits, and in particular relates to a bridgeless boost rectifier circuit for a low-voltage energy recovery source. Background Art

[0002] As artificial intelligence and big data models become more mature, the Internet of Everything will become an important development trend of artificial intelligence and big data models in the future. Artificial intelligence and big data models need to rely on early data collection to build data sets for training. However, how to power data collection sensors in a variety of complex environments is an urgent problem to be solved.

[0003] In addition, the energy-saving and environmental protection concept advocated by carbon neutrality and carbon peak is popular around the world. The traditional limited power supply scheme cannot efficiently power the data acquisition sensors in complex environments. Therefore, there is a non-transmission line power supply technology solution that collects weak energy (such as vibration, temperature difference, water flow, solar energy, etc.) in various environments as the power supply for data sensors.

[0004] The existing solution of realizing power supply technology without transmission line based on weak environmental energy mainly uses a small power generation device to generate a low-voltage AC output voltage, such as 0.4 or 0.7V peak AC. Then, through the AC-DC conversion circuit, a stable low-voltage (such as 3.3V) output is achieved to power the subsequent battery pack and load. However, this type of solution has the following problems, which is not conducive to efficient energy conversion.

[0005] (1) The traditional bridgeless conversion circuit still requires an input diode, which causes the diode conduction voltage drop to consume the low-voltage AC power recovered by the power generation device, making it impossible for the circuit to operate normally.

[0006] (2) Since the AC voltage generated by the power generation device is extremely low, it is not possible to efficiently or even impossible to use a traditional rectifier bridge to achieve AC-DC due to the diode conduction voltage drop of the diode rectifier bridge.

[0007] The present invention proposes a bridgeless boost rectifier circuit for a low-voltage energy recovery source, which can solve the problem that the low-voltage AC input of a low-voltage power generation device cannot be efficiently converted, and through a single-stage boost circuit, the low-voltage AC input can be further converted into 3.3V DC for use by a subsequent battery or load. Summary of the invention

[0008] The purpose of the present invention is to provide a bridgeless boost rectifier circuit for a low-voltage energy recovery source to solve the problem in the prior art that the low-voltage AC input of a low-voltage power generation device cannot be efficiently converted as mentioned in the above background technology.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] Bridgeless boost rectifier circuit for low voltage energy recovery source, including inductor L 1. Inductor L 2. Switching tube S 1. Switching tube S 2. Output diode D 1. Output diode D 2. Output capacitor C o ;

[0011] The switch tube S 2. Inductor L 2. Output diode D 2 form a Buck-boost unit, the Buck-boost unit and the output capacitor C o Connection to achieve power conversion within the positive half cycle of AC input;

[0012] The switch tube S 1. Inductor L 1. Output diode D 1 constitutes a Boost unit, the Boost unit and the output capacitor C o Connection is used to realize power conversion within the negative half cycle of AC input.

[0013] Preferably, the input end is connected to the switch tube S 2 drain, inductor L 1, the switch tube S 2 source and output diode D 2 cathode, inductor L One end of 2 is connected;

[0014] The other end of the input is connected to the switch tube S 1's drain, inductor L 2, the other end of the output capacitor C o The positive electrode and the load are connected, and the switch tube S 1 source and inductor L The other end of 1, output diode D 1's cathode is connected to the output diode D 1 anode and output diode D 2 anode, output capacitor C o The negative pole of the load is connected to the other end.

[0015] Preferably, the switch tube S 1. Switching tube S The driving signal of 2 is as follows:

[0016] 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 output signal of comparator 1. V comp1 ;

[0017] Input voltage V in The sampled signal is compared with the zero reference signal to generate the output signal of comparator 2 V comp2 ;

[0018] V comp2 and V comp1 The switch tube is generated by the AND gate S 2 driving signal;

[0019] V comp2 After the NOT gate, V comp1 The switch tube is generated by the AND gate S 1 driving signal.

[0020] Preferably, the working mode of the bridgeless boost rectifier circuit for the low-voltage energy recovery source is as follows:

[0021] Working mode 1: switch tube S 2 is in the on state, the input terminal is connected to the inductor L 2Charging, inductor current i L2 Linear rise, output capacitance C o Provide energy for the load;

[0022] Working mode 2: switch tube S 2 This operating mode starts when the output diode is turned off. D 2 conduction is the inductor current i L2 Provides a freewheeling path, stored in the inductor L 2 energy supplies energy to the load, the inductor current i L2 Linear decline;

[0023] Working mode 3: Inductor current i L2 When the linear decrease reaches zero, the working mode starts and the switch tube S 2 and output diode D 2 are both in the off state, the output capacitorC o Provide energy for the load;

[0024] Working mode 4: switch tube S 1 is in the on state, the input terminal is connected to the inductor L 1 Charging, inductor current i L1 Linear rise, output capacitance C o Provide energy for the load;

[0025] Working mode 5: switch tube S 1 This operating mode starts when the output diode is turned off. D 1 is the inductor current i L1 Provides a freewheeling path, input terminal and storage in the inductor L 1's energy supplies energy to the load, and the inductor current i L1 Linear decline;

[0026] Working mode 6: Inductor current i L1 When the linear decrease reaches zero, the working mode starts and the switch tube S 1 and output diode D 1 are both in the off state, the output capacitor C o Provide energy for the load.

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

[0028] (1) Compared with most existing bridgeless converters, the present invention completely eliminates the diode rectifier bridge, thereby improving the overall efficiency of the conversion circuit.

[0029] (2) The circuit structure of the present invention is simple, the number of components is small, the cost is low, and the volume is small, which is suitable for the application scenario of weak electric energy recovery and utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the bridgeless boost rectifier circuit in the present invention;

[0031] Figure 2 is an equivalent circuit diagram of the working mode of the bridgeless boost rectifier circuit in the present invention in the positive half cycle;

[0032] Figure 3 is an equivalent circuit diagram of the working mode of the bridgeless boost rectifier circuit in the negative half cycle of the present invention;

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

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

[0035] Figure 6 This is a waveform simulation diagram of key components of the bridgeless boost 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] A bridgeless boost rectifier circuit for low voltage energy recovery source, mainly including an inductor L 1. Inductor L 2. Switching tube S 1. Switching tube S 2. Output diode D 1. Output diode D 2. Output capacitor C o . Switching tube S 2. Inductor L 2. Output diode D 2 forms a Buck-boost unit, a switch tube S 1. Inductor L 1. Output diode D 1 constitutes a Boost unit.

[0039] Specifically, the switch S 2. Drain and inductance L 1 and the input end are connected; the switch tube S 2 source and output diode D 2 cathode, inductor L One end of 2 is connected; inductor L 2 and the other end of the input, output capacitor C o The positive pole, the load end, the switch tube S 1's drain connection; switch tube S 1 source and inductor L The other end of 1, output diode D 1 cathode connection; output diode D 1 anode and output diode D2 anode, output capacitor C o The negative pole of the load is connected to the other end.

[0040] It should be noted that the AC-DC bridgeless converter circuit of the present invention does not require an input LC filter circuit because it is applied to the field of low-voltage energy recovery, and the body diode of the switch tube cannot reach the forward conduction voltage and is in an off state. Figure 1 As shown in the figure, since the input voltage of the energy recovery device is low, the body diode of the MOSFET switch tube cannot be turned on and can be omitted. Figure 1 The body diode of the switch tube is marked in gray.

[0041] To illustrate the working principle of the bridgeless boost rectifier circuit without rectifier diodes of the present invention, the circuit can be equivalent to the following: Figure 2-Figure 3 The circuit operating mode diagram is shown.

[0042] Figure 2 (a) is the equivalent circuit of the bridgeless boost rectifier circuit in working mode 1 in the positive half cycle. Figure 2 (b) is the equivalent circuit of working mode 2 of the bridgeless boost rectifier circuit in the positive half cycle. Figure 2 (c) is the equivalent circuit of the bridgeless boost rectifier circuit in working mode 3 in the positive half cycle. Figure 3 (a) is the equivalent circuit of the bridgeless boost rectifier circuit in working mode 4 in the negative half cycle. Figure 3 (b) is the equivalent circuit of the bridgeless boost rectifier circuit in working mode 5 in the negative half cycle. Figure 3 (c) is the equivalent circuit of the bridgeless boost rectifier circuit in working mode 6 in the negative half cycle.

[0043] Depend on Figure 2-Figure 3 The working mode of the device can obtain the key device waveform. Figure 4 (a) is the waveform diagram of the key components of the bridgeless boost rectifier circuit in the positive half cycle of the AC input. Figure 4 (b) is the waveform diagram of the key components of the bridgeless boost rectifier circuit during the negative half cycle of the AC input.

[0044] Working mode 1 [0, d S2 T S ]: In this stage, the switch tube S 2 is in the on state, the input terminal is connected to the inductor L 2Charging, inductor current i L2 Linear increase. Output capacitor C o Provide energy for the load.

[0045] Working mode 2 [ dS2 T S , d S2 T S +d bb T S ]:When the switch tube S 2 is turned off, operating mode 2 begins. Output diode D 2 conduction is the inductor current i L2 Provides a freewheeling path, stored in the inductor L 2 energy supplies energy to the load end, the inductor current i L2 Linear decrease.

[0046] Working mode 3 [ d S2 T S +d bb T S , T S ]:When the inductor current i L2 When the linear decreases to zero, the working mode 3 begins. S 2 and output diode D 2 are both in the off state. Output capacitor C o Provide energy for the load.

[0047] Working mode 4 [0, d S1 T S ]: In this stage, the switch tube S 1 is in the on state, the input terminal is connected to the inductor L 1 Charging, inductor current i L1 Linear increase. Output capacitor C o Provide energy for the load.

[0048] Working mode 5 [ d S1 T S , d S1 T S +d b T S ]:When the switch tubeS 1 is turned off, operating mode 5 begins. Output diode D 1 is the inductor current i L1 Provides a freewheeling path, input terminal and storage in the inductor L 1's energy is supplied to the load end together, and the inductor current i L1 Linear decrease.

[0049] Working mode 6 [ d S1 T S +d b T S , T S ]:When the inductor current i L1 When the linear decreases to zero, the working mode 6 begins. S 1 and output diode D 1 are both in the off state. Output capacitor C o Provide energy for the load.

[0050] The specific control method of the bridgeless boost rectifier circuit in the present invention is as follows: Figure 5 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 output signal of comparator 1. V comp1 On the other hand, the input voltage V in The sampled signal is compared with the "0" reference signal to generate the output signal of comparator 2 V comp2 .

[0051] V comp2 and V comp1 The switch tube is generated by the AND gate S 2 driving signal;

[0052] V comp2 After passing through the NOT gate, V comp1 The switch tube is generated by the AND gate S 1 driving signal.

[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 value is 0.5V, frequency is 600Hz, inductance L 1. L 2 is 4.7uH, output capacitance C o The resistor is 100uF, the output voltage is 3.3V, the load is 300Ω, the power is 36mW, the switching frequency is 47k, and the P in the PI parameters is 0.8 and I is 0.005.

[0055] Figure 6 This is a waveform simulation diagram of the key components of the bridgeless boost rectifier circuit. Figure 6 It can be seen that under the condition of AC input peak value of 0.5V and frequency of 600Hz, the bridgeless boost rectifier circuit achieves a 3.3V regulated output. S 1. Switching tube S 2 respectively at the input voltage v in The positive and negative half-cycles work alternately, realizing AC-DC conversion operation without a rectifier bridge. Moreover, the simulation waveforms of each device are stable, indicating that the rectifier circuit can operate stably. The simulation waveforms of each device are consistent with Figure 4 This is consistent with the theoretical waveform shown.

[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 bridgeless boost rectifier circuit for low voltage energy recovery source, characterized in that: Including inductor L 1. Inductor L 2. Switching tube S 1. Switching tube S 2. Output diode D 1. Output diode D 2. Output capacitor C o ; The switch tube S 2. Inductor L 2. Output diode D 2 form a Buck-boost unit, the Buck-boost unit and the output capacitor C o Connection to achieve power conversion within the positive half cycle of AC input; The switch tube S 1. Inductor L 1. Output diode D 1 constitutes a Boost unit, the Boost unit and the output capacitor C o Connection to achieve power conversion within the negative half cycle of AC input; The input end and the switch tube S 2 drain, inductor L 1, the switch tube S 2 source and output diode D 2 cathode, inductor L One end of 2 is connected; The other end of the input is connected to the switch tube S 1's drain, inductor L The other end of 2, output capacitor C o The positive electrode and the load are connected, and the switch tube S 1 source and inductor L The other end of 1, output diode D 1's cathode is connected to the output diode D 1 anode and output diode D 2 anode, output capacitor C o The negative pole of the load is connected to the other end; The switch tube S 1. Switching tube S The driving signal of 2 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 output signal of comparator 1. V comp1 ; Input voltage V in The sampled signal is compared with the zero reference signal to generate the output signal of comparator 2 V comp2 ; V comp2 and V comp1 The switch tube is generated by the AND gate S 2 driving signal; V comp2 After the NOT gate, V comp1 The switch tube is generated by the AND gate S 1 driving signal.

2. The bridgeless boost rectifier circuit for low-voltage energy recovery source according to claim 1, characterized in that: Its working mode is as follows: Working mode 1: switch tube S 2 is in the on state, the input terminal is connected to the inductor L 2Charging, inductor current i L2 Linear rise, output capacitance C o Provide energy for the load; Working mode 2: switch tube S 2 This operating mode starts when the output diode is turned off. D 2 conduction is the inductor current i L2 Provides a freewheeling path, stored in the inductor L 2 energy supplies energy to the load, the inductor current i L2 Linear decline; Working mode 3: Inductor current i L2 When the linear decrease reaches zero, the working mode starts and the switch tube S 2 and output diode D 2 are both in the off state, the output capacitor C o Provide energy for the load; Working mode 4: switch tube S 1 is in the on state, the input terminal is connected to the inductor L 1 Charging, inductor current i L1 Linear rise, output capacitance C o Provide energy for the load; Working mode 5: switch tube S 1 This operating mode starts when the output diode is turned off. D 1 is the inductor current i L1 Provides a freewheeling path, input terminal and storage in the inductor L 1's energy supplies energy to the load, and the inductor current i L1 Linear decline; Working mode 6: Inductor current i L1 When the linear decrease reaches zero, the working mode starts and the switch tube S 1 and output diode D 1 are both in the off state, the output capacitor C o Provide energy for the load.

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