Direct-current boost circuit considering high precision and wide range operation mode

Abstract

The utility model discloses a kind of direct current BOOST circuit giving consideration to high precision and wide-range operation mode, including direct current power supply, the positive pole of direct current power supply is electrically connected the drain of first switch tube and the positive pole of first diode, the negative pole of direct current power supply is electrically connected the source of second switch tube, one end of second capacitor and the negative pole of load;The drain of second switch tube is electrically connected the source of first switch tube, the source of third switch tube and one end of first capacitor, the negative pole of first diode is electrically connected the other end of first capacitor and one end of inductance;The other end of inductance is electrically connected the positive pole of second diode and the drain of third switch tube;The negative pole of second diode is electrically connected the other end of second capacitor and the positive pole of load.For the problem of high precision and wide-range contradiction in traditional photovoltaic power generation system, the BOOST circuit proposed by the utility model, to give consideration to the wide adjustment range and high precision requirement of output voltage, and then improve the economic benefit of photovoltaic power generation system.

Description

Technical Field

[0001] This utility model belongs to the field of electrical engineering, and in particular relates to a DC BOOST circuit that combines high precision and a wide range of operating modes. Background Technology

[0002] BOOST circuits are widely used in photovoltaic power generation systems, often for maximum power point tracking. BOOST circuits offer high control precision, enabling them to more accurately search for the maximum power point and achieve maximum solar energy conversion efficiency. BOOST circuits also have a wide output voltage range, allowing photovoltaic inverters to be compatible with a wide range of photovoltaic intensity, resulting in longer effective operating times and greater solar energy conversion for the photovoltaic power generation system. However, a wide range and high precision are contradictory. Therefore, this invention proposes a novel BOOST circuit that balances high precision and a wide range to maximize the output power of the photovoltaic power generation system and generate greater economic benefits. Utility Model Content

[0003] To address the aforementioned issues, this utility model discloses a DC BOOST circuit that balances high precision with a wide operating range.

[0004] To achieve the above objectives, the technical solution of this utility model is as follows: A DC boost circuit that balances high precision and a wide operating range includes a DC power supply, the positive terminal of which is electrically connected to the drain of a first switching transistor and a first diode. D 1 The positive terminal of the DC power supply is electrically connected to the source of the second switching transistor and the second capacitor. C 2 one end and load R L The negative terminal of the first switch; the drain of the second switch is electrically connected to the source of the first switch, the source of the third switch, and the first capacitor. C 1 One end, the first diode D 1 The negative terminal is connected to the first capacitor. C 1 The other end and the inductor L One end; inductor L The other end is electrically connected to the second diode. D 2 The positive terminal of the first diode and the drain of the third switching transistor; the second diode. D 2 The negative terminal is electrically connected to the second capacitor. C 2 The other end and load R L The positive pole.

[0005] In a further improvement, the first switching transistor is a first MOSFET. Q 1 .

[0006] In a further improvement, the second switching transistor is a second MOSFET. Q 2 .

[0007] In a further improvement, the third switching transistor is a third MOSFET. Q3 .

[0008] Advantages of this utility model: To address the inherent contradiction between high precision and wide range in traditional photovoltaic power generation systems, this invention proposes a BOOST circuit that balances a wide adjustable range of output voltage with high precision requirements, thereby improving the economic efficiency of photovoltaic power generation systems. Attached Figure Description

[0009] Figure 1: Circuit diagram of this utility model.

[0010] Figure 2: Circuit diagram of switching mode 1.

[0011] Figure 3: Circuit diagram of switching mode 2.

[0012] Figure 4: Circuit diagram of switching mode 3. Detailed Implementation

[0013] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0014] like Figure 1 The DC BOOST circuit shown here combines high precision and a wide operating range, including a DC power supply, the positive terminal of which is electrically connected to a first MOSFET. Q 1 drain and first diode D 1 The positive terminal of the DC power supply is electrically connected to the negative terminal of the second MOSFET. Q 2 The source, the second capacitor C 2 one end and load R L The negative terminal; the second MOSFET Q 2 The drain of the first MOSFET is electrically connected. Q 1 The source of the third MOSFET Q3 The source and the first capacitor C 1 One end, the first diode D 1 The negative terminal is connected to the first capacitor.C 1 The other end and the inductor L One end; inductor L The other end is electrically connected to the second diode. D 2 The positive electrode and the third MOSFET Q3 The drain of the second diode; D 2 The negative terminal is electrically connected to the second capacitor. C 2 The other end and load R L The positive pole.

[0015] The control method for the above circuit is as follows: set up Q 1 — Q 3 The drive signals are respectively S 1 — S 3 S x=1--3 =1 indicates that the drive signal is high; S x=1--3 =0 indicates that the drive signal is low. The DC power supply voltage is Us The large capacitance of capacitor C2 causes capacitor C2 to be in close contact with the load. R L Terminal voltage stabilization U o nearby.

[0016] like Figure 2 As shown, switching mode 1: S 1 =0, S 2 =1, S 3 When =1, the current path in the circuit is Figure 2 At this time, the DC power supply and the capacitor C 1 Parallel connection, simultaneously supplying inductors L With capacitor C 1 Charging. Inductor L The voltage across the two ends is Us ,capacitance C 1 Charged to U s Meanwhile, capacitor C 2 Stable load R L Terminal voltage is U o .

[0017] like Figure 3 As shown, switching mode 2: S 1 =0, S 2 =1, S 3 When =0, the current path in the circuit is Figure 3 At this time, the capacitor C 1 Connected in parallel with a DC power supply, capacitor C 1 Charging voltage to U s Meanwhile, inductors L Through diode D 1 With capacitor C 2 When connected, the voltage across its terminals is U s - Vo Meanwhile, capacitor C 2 Stable load R L exist Uo .

[0018] like Figure 4 As shown, switching mode 3: S 1 =1, S 2 =0, S 3 When =0, the current path in the circuit is Figure 4 At this time, the capacitor C 1 In series with a DC voltage. Inductor L Give capacitor C 2 Charging, and inductance L The voltage across the terminals is 2. U s - V o Meanwhile, capacitor C 2 Make the load R L Stable at U o .

[0019] Wide-range operation mode: When the system requires a high DC voltage output from the Boost circuit and the control precision requirement is not high, this circuit adopts a wide-range operation mode. That is, the Boost circuit uses switching mode 1 and switching mode 2, where the duty cycle of switching mode 1 is... D1 Based on the volt-second balance principle of inductor L, the output voltage can be obtained. U o The relationship with the DC power supply voltage is as follows: U o = U s / (1- D 1 Theoretically, without considering circuit parasitic parameters, the output voltage... U o The range is U s It can be adjusted up to infinity, and has a wide range of output voltage adjustment.

[0020] High-precision operating mode: When the BOOST circuit adopts a wide-range operating mode, the duty cycle... D 1 When the voltage increases from 0 to 0.5, the output voltage... U o Depend on U s nonlinearly increase to 2U s When using a PI control algorithm, the output voltage control accuracy has limitations, and the duty cycle control voltage is not precise enough. Therefore, the proposed circuit employs switching mode 2 and switching mode 3, where the duty cycle of switching mode 3 is... D 3 , Based on the volt-second balance principle of inductor L, the output voltage can be... U o The relationship with the DC power supply voltage is as follows: U o = Us (1+ D 3 When the duty cycle of switching mode 3 increases from 0 to 1 due to the change in D3, the output voltage... U o Us increases linearly to 2 Us Furthermore, when the same duty cycle is changed, the output voltage changes significantly, and the distinction between output voltage and duty cycle is high, enabling more precise control. However, in high-precision operation mode, the maximum output voltage to input voltage ratio is only 2, limiting the output voltage control range.

[0021] Therefore, based on the converter system's output voltage requirement Us, it is proposed that the BOOST circuit can adopt different operating modes to balance the requirements of accuracy and wide voltage range. When the output voltage is greater than 2Us, the circuit operates in a wide-range operating mode, resulting in a wide output voltage range. Conversely, when the output voltage is between Us and 2Us, the circuit operates in a high-precision operating mode, providing higher control precision.

[0022] Although the embodiments of this utility model have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this utility model. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A DC BOOST circuit that balances high precision and a wide operating range, characterized in that, Includes a DC power supply, the positive terminal of which is electrically connected to the drain of the first switching transistor and the first diode. D 1 The positive terminal of the DC power supply is connected to the source of the second switching transistor, and the negative terminal of the second capacitor. C 2 One end of the load () and the load () R L The negative terminal of the first switch is connected to the negative terminal of the second switch; the drain of the second switch is electrically connected to the source of the first switch, the source of the third switch, and the first capacitor. C 1 One end of the diode ( D 1 The negative terminal of the capacitor is electrically connected to the first capacitor. C 1 The other end of the inductor and the inductor L One end of the inductor; L The other end of the diode is electrically connected to the second diode. D 2 The positive terminal of the first diode and the drain of the third switching transistor; the second diode ( D 2 The negative terminal of the capacitor is electrically connected to the second capacitor. C 2 The other end of the load () R L The positive electrode of ).

2. The DC BOOST circuit as described in claim 1, which combines high precision and a wide operating range, is characterized in that... The first switching transistor is a first MOSFET ( Q 1 ).

3. The DC BOOST circuit as described in claim 1, which combines high precision and a wide operating range, is characterized in that... The second switching transistor is the second MOSFET ( Q 2 ).

4. The DC BOOST circuit as described in claim 1, which combines high precision and a wide operating range, is characterized in that... The third switching transistor is a third MOSFET ( Q3 ).

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