Three-port converter based on solar power generation

Abstract

The utility model provides a three-port converter based on solar power generation, which comprises a photovoltaic array, the positive electrode of the photovoltaic array is sequentially connected in series with an inductor L1, a diode D1, an inductor L2, a diode D2, a diode D3, a diode D4 and the positive electrode of a load R. The negative electrode of the photovoltaic array is connected with the negative electrode of the load R. A capacitor Cpv, a power switch S1, a capacitor CB, a storage battery, a power switch S2, a capacitor C1 and a capacitor C2 are connected between the photovoltaic array and the load R in parallel, the capacitor Cpv is connected to the positive electrode of the photovoltaic array in parallel, the power switch S1 is connected with the positive electrode of the photovoltaic array through an inductor L1, the power switch S2 is connected with an inductor L2 in series and then connected with the capacitor CB in parallel at the two ends of the storage battery, and the capacitor C2 is connected with the capacitor C1. The capacitor C1 and the capacitor C2 are series capacitors and are connected in parallel between the photovoltaic array and the load; according to the three-port converter, a solar power generation system can have efficient and stable performance, and different load requirements can be met.

Description

Technical Field

[0001] The utility model belongs to the technical field of photovoltaic power generation, and in particular relates to a three-port converter based on solar power generation. Background Art

[0002] As human resource consumption increases and non-renewable resources on the earth decrease, the world is looking for new alternative energy sources for humans. As a renewable energy source, solar energy has great room for development. However, photovoltaic cells themselves have problems such as low energy conversion efficiency and poor stability. Therefore, it is particularly important to improve the efficiency of the entire photovoltaic power generation system. Summary of the invention

[0003] The utility model provides a three-port converter based on solar power generation, and realizes a solar power generation system with high efficiency and stable performance through the three-port converter, and can adapt to different load requirements. The specific scheme is as follows:

[0004] A three-port converter based on solar power generation, including a photovoltaic array, wherein the positive electrode of the photovoltaic array is connected in series with an inductor L1, a diode D1, an inductor L2, a diode D2, a diode D3, a diode D4 and a positive electrode of a load R in sequence, the negative electrode of the photovoltaic array is connected to the negative electrode of the load R, a capacitor Cpv positive electrode is connected between the positive electrode of the photovoltaic array and the inductor L1, and a negative electrode is connected between the negative electrode of the photovoltaic array and the negative electrode of the load R, a power switch tube S1 drain electrode is connected to the positive electrode of the diode D1, and a primary electrode is connected between the negative electrode of the photovoltaic array and the negative electrode of the load R, a battery V B The positive electrode is connected between the cathode of the diode D1 and the inductor L2, and the negative electrode is connected between the cathode of the photovoltaic array and the cathode of the load R. The capacitor C is connected between the diode D1 and the inductor L2. B Positive electrode, C B The negative electrode is connected between the negative electrode of the photovoltaic array and the negative electrode of the load R, the drain electrode of the power switch S2 is connected between the inductor L2 and the diode D2, the source electrode of the power switch S2 is connected between the negative electrode of the photovoltaic array and the negative electrode of the load R, the positive electrode of a capacitor C1 is connected to the positive electrode of the diode D2, and the negative electrode is connected to the negative electrode of the diode D3, the negative electrode of the capacitor C2 is connected between the diode D4 and the positive electrode of the load R, the negative electrode of the capacitor C2 is connected to the positive electrode of the capacitor C3, the negative electrode of the capacitor C3 is connected between the negative electrode of the photovoltaic array and the negative electrode of the load R, the negative electrode of the capacitor C2 is connected to the positive electrode of the diode D3, and the power switches S1 and S2 have 4 switching states, the power switch S1 is closed and S2 is disconnected, the power switch S2 is closed and S1 is disconnected, the power switches S1 and S2 are disconnected at the same time, and the power switches S1 and S2 are closed at the same time.

[0005] The beneficial effects of the utility model are:

[0006] The utility model is a three-port converter based on solar power generation, which effectively combines a solar cell panel, a battery energy storage device and a load into three ports, thereby realizing efficient management and electric energy conversion of a solar power generation system, and can work in dual-input, dual-output and single-output modes, and automatically switch among the three modes to realize power flow sharing. The solar power generation system has efficient and stable performance through the three-port converter, and can adapt to different load requirements, and can be applicable to solar power generation systems of various sizes. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 Schematic diagram of the three-port DC converter topology.

[0008] Figure 2 Schematic diagram of the photovoltaic port supplying power to the load independently.

[0009] Figure 3 Schematic diagram of the battery port supplying power to the load separately.

[0010] Figure 4 Schematic diagram of the photovoltaic port supplying power to the load and the battery at the same time.

[0011] Figure 5 Schematic diagram of the photovoltaic port and the battery port supplying power to the load at the same time. DETAILED DESCRIPTION

[0012] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0013] See also Figure 1 A three-port converter based on solar power generation includes a photovoltaic array, wherein the positive electrode of the photovoltaic array is connected in series with an inductor L1, a diode D1, an inductor L2, a diode D2, a diode D3, a diode D4 and a positive electrode of a load R in sequence, and the negative electrode of the photovoltaic array is connected to the negative electrode of the load R. Vpv and ipv are the port voltage and the port current of the photovoltaic array respectively, V0 and i0 are the load voltage and the load current respectively, and i L1 、V L1 are the inductor L1 current and inductor L1 voltage, i L2 、V L2 The positive pole of a capacitor Cpv is connected between the positive pole of the photovoltaic array and the inductor L1, and the negative pole is connected between the negative pole of the photovoltaic array and the negative pole of the load R. The drain of a power switch tube S1 is connected to the positive pole of the diode D1, and the source pole is connected between the negative pole of the photovoltaic array and the negative pole of the load R. A battery V B The positive electrode is connected between the cathode of diode D1 and inductor L2, and the negative electrode is connected between the cathode of photovoltaic array and the cathode of load R.B 、i B The voltage and current of the battery are connected between the diode D1 and the inductor L2. B Positive electrode, C B The negative pole is connected between the negative pole of the photovoltaic array and the negative pole of the load R. The drain of the power switch S2 is connected between the inductor L2 and the diode D2. The source of the power switch S2 is connected between the negative pole of the photovoltaic array and the negative pole of the load R. The positive pole of a capacitor C1 is connected to the positive pole of the diode D2, and the negative pole is connected to the negative pole of the diode D3. V C1 、i C1 are the voltage and current of capacitor C1 respectively. The cathode of capacitor C2 is connected between diode D4 and the anode of load R. C2 、V C2 are the current and voltage of capacitor C2 respectively. The negative electrode of capacitor C2 is connected to the positive electrode of capacitor C3. The negative electrode of capacitor C3 is connected between the negative electrode of the photovoltaic array and the negative electrode of the load R. The negative electrode of capacitor C2 is connected to the positive electrode of diode D3. C3 、V C3 are the current and voltage of capacitor C3 respectively. Power switches S1 and S2 have four switching states: power switch S1 is closed and S2 is open, power switch S2 is closed and S1 is open, power switches S1 and S2 are open at the same time, and power switches S1 and S2 are closed at the same time.

[0014] See also Figure 2 As shown, the PV port independently provides energy to the load. At this time, the PV array has enough energy to meet the load consumption, and the battery does not need to be charged, that is, Ppv = P0. In this mode, the converter can be equivalent to a single input single output (SISO) converter.

[0015] See also Figure 3 As shown, the battery port independently provides energy to the load. This working mode usually occurs at night, when the photovoltaic array cannot provide energy and the load power can only be provided by the battery, that is, P B =P0, in this mode the converter can also be equivalent to a SISO converter.

[0016] See also Figure 4 As shown, the photovoltaic port supplies power to the battery and the load at the same time. At this time, the energy that the photovoltaic port can provide is greater than the load demand. While meeting the load power, the unconsumed energy is stored in the battery. The power relationship is Ppv = P B +P0, in this mode the converter is equivalent to a dual-input mode converter.

[0017] See also Figure 5As shown, the photovoltaic port and the battery port supply power to the load at the same time. At this time, the energy provided by the photovoltaic port cannot meet the load demand. The battery needs to provide the energy difference between the load and the photovoltaic port. The power relationship is Ppv+P B =P0, in this mode the converter is equivalent to a dual output mode.

[0018] The working principle, control strategy and circuit topology of the three-port converter: According to the output power of the photovoltaic array, the load power and the state of the storage battery SOC, the power of the three ports is balanced. When the external conditions change, the operating mode of the three-port converter is changed accordingly through a closed-loop control strategy.

[0019] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any reference numerals in the claims should not be regarded as limiting the claims involved.

[0020] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A three-port converter based on solar power generation, characterized in that: The invention comprises a photovoltaic array, wherein the positive electrode of the photovoltaic array is connected in series with an inductor L1, a diode D1, an inductor L2, a diode D2, a diode D3, a diode D4 and a positive electrode of a load R in sequence, the negative electrode of the photovoltaic array is connected to the negative electrode of the load R, a capacitor Cpv is connected between the positive electrode of the photovoltaic array and the inductor L1, and the negative electrode is connected between the negative electrode of the photovoltaic array and the negative electrode of the load R, a power switch tube S1 drain is connected to the positive electrode of the diode D1, and the primary electrode is connected between the negative electrode of the photovoltaic array and the negative electrode of the load R, and a battery V B The positive electrode is connected between the cathode of the diode D1 and the inductor L2, and the negative electrode is connected between the cathode of the photovoltaic array and the cathode of the load R. The capacitor C is connected between the diode D1 and the inductor L2. B Positive electrode, C B The negative electrode is connected between the negative electrode of the photovoltaic array and the negative electrode of the load R, the drain electrode of the power switch S2 is connected between the inductor L2 and the diode D2, the source electrode of the power switch S2 is connected between the negative electrode of the photovoltaic array and the negative electrode of the load R, the positive electrode of a capacitor C1 is connected to the positive electrode of the diode D2, and the negative electrode is connected to the negative electrode of the diode D3, the negative electrode of the capacitor C2 is connected between the diode D4 and the positive electrode of the load R, the negative electrode of the capacitor C2 is connected to the positive electrode of the capacitor C3, the negative electrode of the capacitor C3 is connected between the negative electrode of the photovoltaic array and the negative electrode of the load R, the negative electrode of the capacitor C2 is connected to the positive electrode of the diode D3, and the power switches S1 and S2 have 4 switching states, the power switch S1 is closed and S2 is disconnected, the power switch S2 is closed and S1 is disconnected, the power switches S1 and S2 are disconnected at the same time, and the power switches S1 and S2 are closed at the same time.

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