A photovoltaic power supply system

Abstract

The application provides a photovoltaic power supply system, which comprises a photovoltaic module, a battery module and a DCDC conversion assembly; the DCDC conversion assembly comprises a first DCDC conversion module and a second DCDC conversion module; the working mode of the DCDC conversion assembly comprises at least a first working mode and a second working mode; when the DCDC conversion assembly is in the first working mode, the first DCDC conversion module is in a first state, the second DCDC conversion module is in a working state, and the photovoltaic module and the battery module supply power to a load at the same time; when the DCDC conversion assembly is in the second working mode, the first DCDC conversion module is in a second state, the second DCDC conversion module is in a standby state, the photovoltaic module charges the battery module and supplies power to the load. The photovoltaic module can charge the battery module and supply power to the load at the same time, the energy of the photovoltaic module is fully utilized, the conversion efficiency is ensured, and the hardware cost is reduced.

Description

Technical Field

[0001] This application relates to the field of photovoltaic control technology, and in particular to a photovoltaic power supply system. Background Technology

[0002] In existing photovoltaic power generation technology, the light intensity and illuminated area of ​​photovoltaic modules at different locations will change with the rising and setting of the sun throughout the day, and thus the power generation will also change. The intermittent and fluctuating characteristics of photovoltaic power generation restrict its efficient utilization. It is necessary to use energy storage technologies such as battery energy storage systems to effectively smooth out power fluctuations through energy time shifting mechanisms. However, the contradiction between system cost and conversion efficiency has not yet been properly resolved.

[0003] In existing photovoltaic-storage DC microgrids, photovoltaic modules charge battery modules and supply power to loads via two separate DC-DC converters. While this method offers high energy conversion efficiency, the need for a DC-DC converter on each power supply branch results in relatively high equipment costs. This economic issue is particularly prominent in low-cost power solutions for remote areas and developing countries. Currently, the technological bottleneck of photovoltaic-storage microgrids lies in balancing efficiency and cost. Therefore, improving energy conversion efficiency through topology optimization and control strategy improvements without significantly increasing hardware costs has become a key research topic for the large-scale application of photovoltaic-storage DC microgrids. Utility Model Content

[0004] This application discloses a photovoltaic power supply system, which aims to provide a photovoltaic power supply system that can improve the conversion efficiency and system stability of the circuit, while reducing hardware costs.

[0005] To achieve the above objectives, this application discloses a photovoltaic power supply system, which includes a photovoltaic module, a battery module, and a DC-DC converter component, wherein the DC-DC converter component includes a first DC-DC converter module and a second DC-DC converter module.

[0006] The first terminal of the first DC-DC converter module is electrically connected to the positive terminal of the photovoltaic module, the second terminal of the first DC-DC converter module is electrically connected to the positive terminal of the load, the third terminal of the first DC-DC converter module is electrically connected to the positive terminal of the battery module, and the fourth terminal of the first DC-DC converter module is electrically connected to the negative terminals of the photovoltaic module and the battery module.

[0007] The first terminal of the second DC-DC converter module is electrically connected to the positive terminal of the battery module, the second terminal of the second DC-DC converter module is electrically connected to the positive terminal of the load, and the third terminal of the second DC-DC converter module is electrically connected to the negative terminal of the battery module and the negative terminal of the load.

[0008] The DC-DC conversion component has at least a first operating mode and a second operating mode.

[0009] When the DC-DC conversion component is in the first working mode, the first DC-DC conversion module is in the first state, the second DC-DC conversion module is in the working state, and the photovoltaic module and the battery module simultaneously supply power to the load.

[0010] When the DC-DC converter is in the second operating mode, the first DC-DC converter module is in the second state, the second DC-DC converter module is in the standby state, and the photovoltaic module charges the battery module and supplies power to the load.

[0011] In some embodiments, when the output power of the photovoltaic module is less than the power required by the load, the DC-DC converter is in a first operating mode.

[0012] When the output power of the photovoltaic module is greater than the power required by the load, the DC-DC converter is in the second operating mode.

[0013] In some embodiments, the first DC-DC conversion module includes:

[0014] A first inductor module, wherein a first terminal of the first inductor module is electrically connected to the positive terminal of the photovoltaic module;

[0015] A first switch module, wherein a first terminal of the first switch module is electrically connected to a second terminal of the first inductor module, and the second terminal of the first switch module is electrically connected to the negative terminal of the photovoltaic module and the negative terminal of the battery module;

[0016] The fourth switch module has its first terminal electrically connected to the second terminal of the first inductor module, and its second terminal electrically connected to the positive terminal of the battery module.

[0017] The third switch module has a first terminal electrically connected to the second terminal of the first inductor module, and the second terminal of the third switch module is electrically connected to the positive terminal of the load.

[0018] Wherein, the first end of the first inductor module is the first end of the first DC-DC converter module, the second end of the third switch module is the second end of the first DC-DC converter module, the second end of the fourth switch module is the third end of the first DC-DC converter module, and the second end of the first switch module is the fourth end of the first DC-DC converter module.

[0019] In some embodiments, the second DC-DC conversion module includes:

[0020] The second switch module has its first terminal electrically connected to the positive terminal of the battery module.

[0021] The fifth switch module has its second terminal electrically connected to the second terminal of the second switch module, and its first terminal electrically connected to the negative terminal of the battery module and the negative terminal of the load.

[0022] The second inductor module has its first end electrically connected to the second end of the second switch module and the second end of the fifth switch module, and its second end electrically connected to the positive terminal of the load.

[0023] Wherein, the first end of the second switch module is the first end of the second DC-DC converter module, the second end of the second inductor module is the second end of the second DC-DC converter module, and the first end of the fifth switch module is the third end of the second DC-DC converter module.

[0024] In some embodiments, when the first DC-DC conversion module is in the first state, the first DC-DC conversion module repeatedly switches between mode one and mode two;

[0025] When the first DC-DC converter module is in mode one, the first switch module is turned on, the fourth switch module is turned off, the third switch module is turned off, and the photovoltaic module charges the first inductor module.

[0026] When the first DC-DC converter module is in mode two, the first switch module is blocked, the fourth switch module is blocked, the third switch module is turned on, and the photovoltaic module supplies power to the load.

[0027] In some embodiments, when the first DC-DC conversion module is in the second state, the first DC-DC conversion module sequentially switches between mode one, mode two, and mode three; or, when the first DC-DC conversion module is in the second state, the first DC-DC conversion module sequentially switches between mode one, mode two, mode three, and mode two.

[0028] When the first DC-DC converter module is in mode three, the first switch module is blocked, the fourth switch module is turned on, the third switch module is blocked, and the photovoltaic module charges the battery module.

[0029] In some embodiments, the photovoltaic power supply system further includes:

[0030] The first filter module has its first end electrically connected to the positive terminal of the photovoltaic module and the first end of the first inductor module, and its second end electrically connected to the negative terminal of the photovoltaic module and the second end of the first switch module.

[0031] The second filter module has its first end electrically connected to the second end of the fourth switch module and the positive terminal of the battery module, and its second end electrically connected to the second end of the first switch module and the negative terminal of the battery module.

[0032] The third filter module has its first end electrically connected to the second end of the second inductor module and the positive terminal of the load, and its second end electrically connected to the first end of the fifth switch module and the negative input terminal of the load.

[0033] In some embodiments, the first switching module includes a first MOSFET, a first terminal of the first MOSFET being electrically connected to a second terminal of the first inductor module, and the second terminal of the first MOSFET being electrically connected to the negative terminal of the photovoltaic module and the negative terminal of the battery module.

[0034] The fourth switch module includes a fourth diode, the first end of which is electrically connected to the second end of the first inductor module, and the second end of which is electrically connected to the positive terminal of the battery module.

[0035] The third switching module includes a third MOSFET and a sixth diode. The first terminal of the sixth diode is electrically connected to the second terminal of the first inductor module, the second terminal of the sixth diode is electrically connected to the first terminal of the third MOSFET, and the second terminal of the third MOSFET is electrically connected to the positive terminal of the load.

[0036] In some embodiments, the voltage of the photovoltaic module and the voltage across the load are both lower than the voltage of the battery module.

[0037] In some embodiments, the second switching module includes a second MOSFET, the first terminal of which is electrically connected to the positive terminal of the battery module;

[0038] The fifth switching module includes a fifth diode, the second end of which is electrically connected to the second end of the second MOS transistor, and the first end of which is electrically connected to the negative terminal of the battery module and the negative terminal of the load.

[0039] Compared with the prior art, the beneficial effects of this application are as follows:

[0040] The power supply system includes a photovoltaic module, a battery module, and a DC-DC converter assembly. The DC-DC converter assembly includes a first DC-DC converter module and a second DC-DC converter module. A first terminal of the first DC-DC converter module is electrically connected to the positive terminal of the photovoltaic module; a second terminal of the first DC-DC converter module is electrically connected to the positive terminal of the load; a third terminal of the first DC-DC converter module is electrically connected to the positive terminal of the battery module; and a fourth terminal of the first DC-DC converter module is electrically connected to the negative terminals of both the photovoltaic module and the battery module. A first terminal of the second DC-DC converter module is electrically connected to the positive terminal of the battery module, and a second terminal of the second DC-DC converter module is electrically connected to the positive terminal of the load. The positive terminal is electrically connected, and the third terminal of the second DC-DC converter module is electrically connected to the negative terminal of the battery module and the negative terminal of the load. The DC-DC converter module has at least a first operating mode and a second operating mode. When the DC-DC converter module is in the first operating mode, the first DC-DC converter module is in a first state, the second DC-DC converter module is in an operating state, and the photovoltaic module and the battery module simultaneously supply power to the load. When the DC-DC converter module is in the second operating mode, the first DC-DC converter module is in a second state, the second DC-DC converter module is in a standby state, and the photovoltaic module charges the battery module and supplies power to the load.

[0041] As can be seen, this system can enable the photovoltaic module to simultaneously charge the battery module and supply power to the load through the first DC-DC converter module, making full use of the photovoltaic module's energy. Both the charging of the battery module and the power supply to the load by the photovoltaic module are single-stage conversions, which reduces hardware costs while ensuring conversion efficiency. At the same time, the power of the battery can be supplied to the load through the second DC-DC converter module, thereby improving the system's stability. Through the cooperation of the first DC-DC converter module and the second DC-DC converter module, the voltage regulation range of the photovoltaic module can be greatly improved. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of one embodiment of this application;

[0044] Figure 2 This is a schematic diagram of yet another embodiment of this application;

[0045] Figure 3This is a schematic diagram of another embodiment of this application;

[0046] Figure 4 This is a schematic diagram of another embodiment, mode one, of this application;

[0047] Figure 5 This is a schematic diagram of another embodiment, mode two, of this application;

[0048] Figure 6 This is a schematic diagram of another embodiment, mode three, of this application;

[0049] Figure 7 This is a schematic diagram of another embodiment of the present application including a filtering module;

[0050] Figure 8 This is the circuit diagram of this application;

[0051] Figure 4-6 The red line in the middle is used to identify the current in the circuit.

[0052] Explanation of main figure symbols

[0053] 1-Photovoltaic module, 2-Battery module, 5-Load;

[0054] 3-First DC-DC converter module, 31-First inductor module, 32-Third switch module, 33-Fourth switch module, 34-First switch module;

[0055] 4-Second DC-DC converter module, 41-Second switch module, 42-Fifth switch module, 43-Second power supply module

[0056] Sensing module;

[0057] 61-First filtering module, 62-Second filtering module, 63-Third filtering module. Detailed Implementation

[0058] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0059] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the specific technical solutions of this application will be further described in detail below with reference to the accompanying drawings of the embodiments of this application. The following embodiments are used to illustrate this application, but are not intended to limit the scope of this application.

[0060] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0061] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0062] It should be noted that the terms "first, second, third" used in the embodiments of this application are used to distinguish similar or different objects and do not represent a specific order of objects. It can be understood that "first, second, third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0063] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0064] like Figure 1-8 As shown, this application provides a photovoltaic power supply system, including a photovoltaic module 1, a battery module 2, and a DC-DC converter assembly. The DC-DC converter assembly includes a first DC-DC converter module 3 and a second DC-DC converter module 4.

[0065] The first terminal of the first DC-DC converter module 3 is electrically connected to the positive terminal of the photovoltaic module 1, the second terminal of the first DC-DC converter module 3 is electrically connected to the positive terminal of the load 5, the third terminal of the first DC-DC converter module 3 is electrically connected to the positive terminal of the battery module 2, and the fourth terminal of the first DC-DC converter module 3 is electrically connected to the negative terminals of the photovoltaic module 1 and the battery module 2.

[0066] The first terminal of the second DC-DC converter module 4 is electrically connected to the positive terminal of the battery module 2, the second terminal of the second DC-DC converter module 4 is electrically connected to the positive terminal of the load 5, and the third terminal of the second DC-DC converter module 4 is electrically connected to the negative terminal of the battery module 2 and the negative terminal of the load 5.

[0067] The operating modes of the DC-DC conversion component include at least a first operating mode and a second operating mode;

[0068] When the DC-DC converter is in the first working mode, the first DC-DC converter module 3 is in the first state, the second DC-DC converter module 4 is in the working state, and the photovoltaic module 1 and the battery module 2 simultaneously supply power to the load 5.

[0069] When the DC-DC converter is in the second working mode, the first DC-DC converter module 3 is in the second state, the second DC-DC converter module 4 is in the standby state, and the photovoltaic module 1 charges the battery module 2 and supplies power to the load 5.

[0070] It should be noted that throughout the entire operation of this system, the voltage of photovoltaic module 1 and the voltage across the load terminals are both lower than the voltage of battery module 2.

[0071] When the DC-DC converter is in the first operating mode, the second DC-DC converter module 4 being in operation means that the second DC-DC converter module 4 converts the output voltage or current of the battery module 2 to the voltage or current required by the load 5 and supplies power to the load 5. When the DC-DC converter is in the second operating mode, the second DC-DC converter module 4 being in standby mode means that the second DC-DC converter module 4 is in a non-operating state, that is, at this time, the second DC-DC converter module 4 does not convert the output voltage of the battery module 2, nor does it supply power to the load 5.

[0072] The positive and negative terminals of load 5 are two ports on load 5 that are connected to the power supply. The positive terminal is connected to the positive terminal of the power supply, and the negative terminal is connected to the negative terminal of the power supply.

[0073] When the output power of photovoltaic module 1 is greater than the power required by the load, the system can enable photovoltaic module 1 to charge battery module 2 and supply power to load 5 through the first DC-DC conversion module 3. That is, when photovoltaic module 1 charges battery module 2, it also supplies power to load 5 at the same time. The power distribution of photovoltaic module 1 can be realized through the first DC-DC conversion module 3.

[0074] In some embodiments, photovoltaic module 1 can be a single photovoltaic power source, or a power supply system composed of multiple photovoltaic power sources connected in series, parallel, or a series-parallel combination. In some embodiments, battery module 2 can be a single battery, or a power supply system composed of multiple battery modules connected in series, parallel, or a series-parallel combination. It should be further noted that, as... Figure 8 As shown, the DC port is used to electrically connect to the positive terminal of the load 5, the PV port is used to electrically connect to the photovoltaic module 1, and BAT is the battery module 2.

[0075] Furthermore, it can be understood that load 5 is the primary load and battery module 2 is the secondary load. Only when the power of photovoltaic module 1 fully meets the power demand of load 5, photovoltaic module 1 transmits power to load 5 and also transmits power to battery module 2. That is, at this time, load 5 can work normally using the power generated by photovoltaic module 1, and battery module 2 can charge using the power generated by photovoltaic module 1.

[0076] Therefore, in this system, photovoltaic module 1 can charge battery module 2 and supply power to load 5 through a single-stage conversion of the first DC-DC converter module 3. This reduces hardware costs while ensuring conversion efficiency and improves the power conversion range of photovoltaic module 1, ensuring that the electrical energy of photovoltaic module 1 is fully utilized. The cooperation between the first DC-DC converter module 3 and the second DC-DC converter module can significantly improve the voltage regulation range of the photovoltaic module.

[0077] In some embodiments, when the output power of photovoltaic module 1 is less than the power required by load 5, the DC-DC conversion component is in a first operating mode.

[0078] When the output power of photovoltaic module 1 is greater than the power required by load 5, the DC-DC converter is in the second working mode.

[0079] Furthermore, the output power of photovoltaic module 1 is greater than the input power required by load 5, including two cases:

[0080] When the output power of photovoltaic module 1 is greater than the power required by load 5, but less than the sum of the power required by load 5 and the charging power required by battery module 2, the DC-DC converter is in the second working mode, and there is no need to limit the power of photovoltaic module 1.

[0081] When the output power of photovoltaic module 1 is greater than the sum of the power required by load 5 and the charging power required by battery module 2, the DC-DC converter is in the second working mode. At this time, the power of photovoltaic module 1 needs to be limited to avoid damage to battery module 2 or load 5 due to excessive output power.

[0082] refer to Figure 2 Furthermore, the first DC-DC conversion module 3 includes:

[0083] The first inductor module 31, the first end of the first inductor module 31 is electrically connected to the positive terminal of the photovoltaic module 1;

[0084] The first switch module 34 has its first end electrically connected to the second end of the first inductor module 31, and its second end electrically connected to the negative terminal of the photovoltaic module 1 and the negative terminal of the battery module 2.

[0085] The first terminal of the fourth switch module 33 is electrically connected to the second terminal of the first inductor module 31, and the second terminal of the fourth switch module 33 is electrically connected to the positive terminal of the battery module 2.

[0086] The third switch module 32 has its first end electrically connected to the second end of the first inductor module 31, and its second end electrically connected to the positive terminal of the load 5.

[0087] Wherein, the first end of the first inductor module 31 is the first end of the first DC-DC converter module 3, the second end of the third switch module 32 is the second end of the first DC-DC converter module 3, the second end of the fourth switch module 33 is the third end of the first DC-DC converter module 3, and the second end of the first switch module 34 is the fourth end of the first DC-DC converter module 3.

[0088] refer to Figure 4-5 In some embodiments, when the first DC-DC conversion module 3 is in the first state, the first DC-DC conversion module 3 repeatedly switches between mode one and mode two;

[0089] When the first DC-DC converter module 3 is in mode one, the first switch module 34 is turned on, the fourth switch module 33 is turned off, the third switch module 32 is turned off, and the photovoltaic module 1 charges the first inductor module 31.

[0090] When the first DC-DC converter module 3 is in mode two, the first switch module 34 is blocked, the fourth switch module 33 is blocked, the third switch module 32 is turned on, and the photovoltaic module 1 supplies power to the load 5.

[0091] It should be noted that when the first DC-DC converter module 3 is in the first state, the first DC-DC converter module 3 repeatedly switches between mode one and mode two. At this time, the photovoltaic module 1 only supplies power to the load 5, and the power of the photovoltaic module 1 cannot meet the power demand of the load 5. The insufficient power needs to be provided by the battery module 2.

[0092] When the first DC-DC converter module 3 is in mode one, the first switch module 34 is turned on, the fourth switch module 33 is turned off, and the third switch module 32 is turned off. The current flows out from the positive terminal of the photovoltaic module 1, passes through the first inductor module 31, and returns to the negative terminal of the photovoltaic module 1 through the first switch module 34, so that the photovoltaic module 1 charges the first inductor module 31.

[0093] When the first DC-DC converter module 3 is in mode two, the first switch module 34 is blocked, the fourth switch module 33 is blocked, and the third switch module 32 is turned on. The current flows out from the positive terminal of the photovoltaic module 1, passes through the first inductor module 31, the third switch module 32, and the load 5, and returns to the negative terminal of the photovoltaic module 1. At this time, the photovoltaic module 1 can supply power to the load 5, and at the same time, the energy stored by the first inductor module 31 in mode one is supplied to the load 5.

[0094] It should be noted that the output voltage or output current of photovoltaic module 1 is adjusted by coordinating mode one and mode two to supply the load 5. By adjusting the duty cycle of the first switch module 34 or the third switch module 32, the maximum power point of photovoltaic module 1 is tracked and its entire value is output to the load 5.

[0095] refer to Figure 6 In some embodiments, when the first DC-DC conversion module 3 is in the second state, the first DC-DC conversion module 3 sequentially switches between mode one, mode two, and mode three; or, when the first DC-DC conversion module 3 is in the second state, the first DC-DC conversion module 3 sequentially switches between mode one, mode two, mode three, and mode two.

[0096] When the first DC-DC converter module 3 is in mode three, the first switch module 34 is blocked, the fourth switch module 33 is turned on, the third switch module 32 is blocked, and the photovoltaic module 1 charges the battery module 2.

[0097] It should be noted that when the first DC-DC converter module 3 is in the second state, the photovoltaic module 1 supplies power to the load 5 and charges the battery module 2. Before the first DC-DC converter module 3 enters the third mode, it must first go through the first mode to allow the first inductor module 31 to accumulate energy. After the first inductor 31 has accumulated energy, the first DC-DC converter module 3 first enters the second mode to supply power to the load 5, and then enters the third mode to charge the battery module 2.

[0098] When the first DC-DC converter module 3 is in mode three, the first switch module 34 is blocked, the fourth switch module 33 is turned on, and the third switch module 32 is blocked. The current flows from the positive terminal of the photovoltaic module 1 through the first inductor module 31, the fourth switch module 33, and the battery module 2, and then flows back to the negative terminal of the photovoltaic module 1, so that the photovoltaic module 1 can charge the load 5. At this time, the excess energy stored by the first inductor module 31 in mode one is also supplied to the load 5.

[0099] When the output power of photovoltaic module 1 is insufficient to simultaneously meet the power consumption of load 5 and the charging power requirements of battery module 2, there is no need to limit the power.

[0100] It should be noted that the first DC-DC conversion module 3 cycles through mode one, mode two, and mode three in sequence. By controlling the duty cycle of the first switch module 34, the third switch module 32, and the fourth switch module 33, the maximum power point tracking of the photovoltaic module 1 can be achieved, and the power distribution of the photovoltaic module 1 can be realized, allocating the excess power to the battery module 2 for storage.

[0101] In some embodiments, when the first DC-DC converter module 3 is in the second state, it sequentially switches between mode one, mode two, mode three, and mode two again. By controlling the duty cycle of the first switch module 34, the first duty cycle of the third switch module 32, the duty cycle of the fourth switch module 33, and the second duty cycle of the third switch module 32, maximum power point tracking of the photovoltaic module 1 can be achieved, simultaneously realizing power distribution of the photovoltaic module 1 and allocating excess power to the battery module 2 for storage. Under this mode cycle, the voltage at the second terminal of the first inductor module 31 is lowest in mode one, gradually increases in mode two, and highest in mode three. Then, when entering mode two, the voltage at the second terminal of the inductor module 31 decreases, and then the next cycle begins before entering mode one, where the voltage at the second terminal of the inductor module 31 drops to its lowest point. This gradual increase and decrease in the voltage at the second terminal of the inductor module 31 effectively reduces the impact of voltage fluctuations on electronic components, reduces harmonics, and improves the stability and lifespan of the equipment.

[0102] In some embodiments, when the first DC-DC conversion module 3 is in the second state, the first DC-DC conversion module 3 sequentially switches between mode one, mode three, and mode two.

[0103] Furthermore, when the maximum power point of photovoltaic module 1 exceeds the power consumption of load 5 and the charging power requirement of battery module 2, a power limit control needs to be added on the original basis to achieve the purpose of simultaneously limiting the power of photovoltaic module 1 and distributing the output power of photovoltaic module 1.

[0104] It should be noted that "conduction" means that current can flow through the corresponding switching module to form a circuit, while "blocking" means that current cannot flow through the corresponding switching module to form a circuit.

[0105] In some embodiments, when the load 5 is not working, the first DC-DC converter module 3 is in the third state. At this time, the photovoltaic module 1 charges the battery module 2 through the first DC-DC converter module 3. At this time, the first DC-DC converter module 3 repeatedly switches between mode one and mode three, thereby controlling the magnitude of the output voltage or current of the photovoltaic module 1 to supply the battery module 2.

[0106] It should be noted that when photovoltaic module 1 and battery module 2 simultaneously supply power to load 5, it means that both photovoltaic module 1 and battery module 2 can supply power to load 5 within a certain period of time. This period of time refers to one cycle in which the first DC-DC conversion module 3 sequentially switches between mode 1, mode 2, and mode 3, or one cycle in which it sequentially switches between mode 1, mode 2, mode 3, and mode 2, or one cycle in which it sequentially switches between mode 1, mode 3, and mode 2.

[0107] In some embodiments, the first switch module 34, the third switch module 32, the fourth switch module 33, the second switch module 41, and the fifth switch module 42 all include switching transistors. The first switch module 34, the third switch module 32, the fourth switch module 33, the second switch module 41, the second switch module 41, and the fifth switch module 42 can be a single switching transistor or a combination of multiple switching transistors connected in parallel. In some embodiments, some switch modules can also be diodes. The types of switching transistors include, but are not limited to, insulated-gate bipolar transistors (IGBTs), bipolar transistors (BPTs), MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), and thyristors, as long as they can achieve high-frequency switching functionality.

[0108] Furthermore, the first switching module 34 includes a first MOSFET Q1, the first end of the first MOSFET Q1 is electrically connected to the second end of the first inductor module 31, and the second end of the first MOSFET Q1 is electrically connected to the negative terminal of the photovoltaic module 1 and the negative terminal of the battery module 2.

[0109] The fourth switch module 33 includes a fourth diode D1. The first end of the fourth diode D1 is electrically connected to the second end of the first inductor module 31, and the second end of the fourth diode D1 is electrically connected to the positive terminal of the battery module 2.

[0110] The third switch module 32 includes a third MOSFET Q and a sixth diode D3. The first end of the sixth diode D3 is electrically connected to the second end of the first inductor module 31, the second end of the sixth diode D3 is electrically connected to the first end of the third MOSFET Q3, and the second end of the third MOSFET Q3 is electrically connected to the positive terminal of the load 5.

[0111] In some embodiments, the first inductor module 31 may be a single inductor or a combination of multiple inductors connected in series or in parallel.

[0112] Preferably, the first inductor module 31 includes a first inductor L1, the first end of the first inductor L1 is electrically connected to the positive electrode of the photovoltaic module 1, and the second end of the first inductor L1 is electrically connected to the first end of the first MOSFET Q1 and the first end of the fourth diode.

[0113] It should be noted that in Mode 1, the second terminal of the first inductor L1 is connected to the negative terminal of the photovoltaic module 1, and the voltage at the second terminal of the first inductor L1 is lower than the voltage of the battery module 2. In this case, the fourth diode D1 is reverse-biased and blocked. In Mode 2, the second terminal of the first inductor L1 is connected to the positive terminal of the load 5, and the voltage at the second terminal of the first inductor L1 is lower than the voltage of the battery module 2. Therefore, the fourth diode D1 is reverse-biased and blocked. In both Mode 1 and Mode 2, the fourth diode is reverse-biased and blocked. In Mode 3, the voltage at the second terminal of the first inductor L1 is higher than the voltage of the battery module 2. Therefore, the fourth diode D1 is conducting.

[0114] It should be noted that in mode one, the voltage at the second terminal of the first inductor L1 is less than the voltage at the positive terminal of the load 5. At this time, the sixth diode D3 is cut off. Therefore, during the transition between mode one and mode two, when the third MOSFET Q3 is closed, the third switch module 32 can be blocked by controlling the first MOSFET Q1 to close, and the third switch module 32 can be turned on by controlling the first MOSFET to open. This can reduce the impact caused by frequent closing and opening of the switch, and at the same time, it can simplify the control logic.

[0115] It should be noted that in mode three, if the third MOSFET Q3 is closed, the second terminal of the first inductor L1 is connected to the positive terminal of the load 5. The voltage at the second terminal of the first inductor L1 is lower than the battery voltage. Therefore, the third MOSFET Q3 needs to be disconnected to enable the fourth switch module 33 to conduct.

[0116] Furthermore, the first switch module 34 in modes one to three can be turned on and off by closing and opening the first MOSFET Q1, and the fourth switch module 33 can be turned on and off by using the forward conduction direction cut-off characteristic of the fourth diode D1. In modes one and two, the third switch module 32 is turned on by controlling the first switch module 34 to turn off, and the third switch module 32 is turned off by controlling the first switch module 34 to turn on. This can reduce the impact caused by frequent closing and opening of the switch, and at the same time, it can simplify the control logic.

[0117] It should be noted that the first terminal of the fourth diode D1 is the anode, and the second terminal of the fourth diode D1 is the cathode.

[0118] Preferably, the third MOSFET Q3 and the first MOSFET Q1 are both P-type MOSFETs, the first terminal of the third MOSFET Q3 and the first terminal of the first MOSFET Q1 are both sources, and the second terminal of the third MOSFET Q3 and the second terminal of the first MOSFET Q1 are both drains.

[0119] In this diode, the first terminal of the sixth diode D3 is the anode, and the second terminal of the sixth diode D3 is the cathode.

[0120] refer to Figure 3 Furthermore, the second DC-DC conversion module 4 includes:

[0121] The second switch module 41, the first end of the second switch module 41 is electrically connected to the positive terminal of the battery module 2;

[0122] The fifth switch module 42 has its second end electrically connected to the second end of the second switch module 41, and its first end electrically connected to the negative terminal of the battery module 2 and the negative terminal of the load 5.

[0123] The second inductor module 43 has its first end electrically connected to the second end of the second switch module 41 and the second end of the fifth switch module 42, and its second end electrically connected to the positive terminal of the load 5.

[0124] Among them, the first end of the second switch module 41 is the first end of the second DC-DC converter module 4, the second end of the second inductor module 43 is the second end of the second DC-DC converter module 4, and the first end of the fifth switch module 42 is the third end of the second DC-DC converter module 4.

[0125] It should be noted that both the first inductor module 31 and the second inductor module 43 may include a single inductor, or a combination of multiple inductors connected in series, parallel, or in series-parallel configurations. No limitation is imposed here. Similarly, the battery module 2 may include a single battery, or a combination of multiple batteries connected in series, parallel, or in series-parallel configurations. In some embodiments, the second inductor module 43 includes a second inductor L2.

[0126] It should be noted that when the power of photovoltaic module 1 is insufficient to maintain the operation of electrical load 5, the missing power can be supplemented by battery module 2. Therefore, power limiting control of photovoltaic module 1 is only required when the power of the photovoltaic module exceeds the charging power of battery module 2 and the power required by load 5. This improves the energy utilization rate of photovoltaic module 1 while ensuring that the energy of battery module 2 can supply load 8, thereby enhancing the stability and reliability of the entire circuit's power supply.

[0127] The second switch module 41 is turned on, and the fifth switch module 42 is turned off. At this time, the current flows out from the positive terminal of the battery module 2 and flows through the second inductor L2. The second inductor L2 stores energy. After that, the second switch module 41 is turned off and the fifth switch module 42 is turned on. In this way, the battery module 2 can supply power to the load 5 by the alternating on and off of the second switch module 41 and the fifth switch module 42.

[0128] refer to Figure 7 Furthermore, the system also includes:

[0129] The first filter module 61 has its first end electrically connected to the positive terminal of the photovoltaic module 1 and the first end of the first inductor module 31, and its second end electrically connected to the negative terminal of the photovoltaic module 1 and the second end of the first switch module 34.

[0130] The second filter module 62 has its first end electrically connected to the second end of the fourth switch module 33 and the positive terminal of the battery module 2, and its second end electrically connected to the second end of the first switch module 34 and the negative terminal of the battery module 2.

[0131] The third filter module 63 has its first end electrically connected to the second end of the second inductor module 43 and the positive terminal of the load 5, and its second end electrically connected to the first end of the fifth switch module 42 and the negative input terminal of the load 5.

[0132] In some embodiments, the first filter module 61 includes a first capacitor C1, which is used to filter out high-frequency noise from the photovoltaic module 1, smooth the output voltage harmonics of the photovoltaic module 1, and stabilize the output voltage of the photovoltaic module 1. The second filter module 62 includes a second capacitor C2, which is used to filter out high-frequency harmonics on the output side, smooth the DC output voltage of the first inductor L1, and provide a stable low voltage for the battery module 2. The third filter module 63 includes a third capacitor C3, which is used to filter out high-frequency harmonics on the output side, smooth the DC output voltage of the second inductor L2, and provide a stable low voltage for the load 5.

[0133] When photovoltaic module 1 supplies power to load 5, the first capacitor C1 and the third capacitor C3 filter the output voltage of photovoltaic module 1 and the output voltage of the power supply circuit, respectively. Through two-stage filtering, a stable voltage is ensured to be supplied to load 5. Similarly, when photovoltaic module 1 supplies power to load 5 and charges battery module 2, at the moment photovoltaic module 1 supplies power to battery module 2, the first capacitor C1 and the second capacitor C2 filter the output voltage of photovoltaic module 1 and the output voltage of the power supply circuit, respectively. Through two-stage filtering, the stability of the power supply voltage is improved.

[0134] In some embodiments, both the second switching module 41 and the fifth switching module 42 include a switching transistor. The second switching module 41, the fifth switching module 42 can be a single switching transistor or a combination of multiple switching transistors connected in parallel. In some embodiments, some switching modules can be diodes. The types of switching transistors include, but are not limited to, insulated-gate bipolar transistors (IGBTs), bipolar transistors (BPTs), MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), and thyristors; any transistor capable of performing high-frequency switching is acceptable.

[0135] Furthermore, the second switching module 41 includes a second MOSFET, the first terminal of which is electrically connected to the positive terminal of the battery module 2;

[0136] The fifth switch module 42 includes a fifth diode D4. The second terminal of the fifth diode D4 is electrically connected to the second terminal of the second MOSFET, and the first terminal of the fifth diode D4 is electrically connected to the negative terminal of the battery module 2 and the negative terminal of the load 5.

[0137] In some embodiments, the fifth switch module 42 includes a fifth diode D4. By utilizing the forward conduction and reverse cutoff characteristics of the diode, the impact caused by frequent closing and opening of the switch can be reduced, and the control logic can be simplified.

[0138] It should be understood that the phrases "one embodiment," "an embodiment," or "some embodiments" mentioned throughout the specification mean that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment," "in one embodiment," or "in some embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above-described embodiments are merely for descriptive purposes and do not represent the superiority or inferiority of the embodiments. The descriptions of the various embodiments above tend to emphasize the differences between the various embodiments; their similarities or commonalities can be referred to mutually, and for the sake of brevity, they will not be repeated here.

[0139] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three kinds of relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist simultaneously, and object B exists alone.

[0140] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0141] The modules described above as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules. They may be located in one place or distributed across multiple network units. Some or all of the modules may be selected to achieve the purpose of this embodiment according to actual needs.

[0142] In addition, each functional module in the various embodiments of this application can be integrated into one processing unit, or each module can be a separate unit, or two or more modules can be integrated into one unit; the integrated modules can be implemented in hardware or in the form of hardware plus software functional units.

[0143] The features disclosed in the several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0144] The above are merely embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A photovoltaic power supply system, characterized in that, It includes a photovoltaic module, a battery module, and a DC-DC converter assembly, wherein the DC-DC converter assembly includes a first DC-DC converter module and a second DC-DC converter module; The first terminal of the first DC-DC converter module is electrically connected to the positive terminal of the photovoltaic module, the second terminal of the first DC-DC converter module is electrically connected to the positive terminal of the load, the third terminal of the first DC-DC converter module is electrically connected to the positive terminal of the battery module, and the fourth terminal of the first DC-DC converter module is electrically connected to the negative terminals of the photovoltaic module and the battery module. The first terminal of the second DC-DC converter module is electrically connected to the positive terminal of the battery module, the second terminal of the second DC-DC converter module is electrically connected to the positive terminal of the load, and the third terminal of the second DC-DC converter module is electrically connected to the negative terminal of the battery module and the negative terminal of the load. The DC-DC conversion component has at least a first operating mode and a second operating mode. When the DC-DC conversion component is in the first working mode, the first DC-DC conversion module is in the first state, the second DC-DC conversion module is in the working state, and the photovoltaic module and the battery module simultaneously supply power to the load. When the DC-DC converter is in the second operating mode, the first DC-DC converter module is in the second state, the second DC-DC converter module is in the standby state, and the photovoltaic module charges the battery module and supplies power to the load.

2. The photovoltaic power supply system according to claim 1, characterized in that, When the output power of the photovoltaic module is less than the power required by the load, the DC-DC converter is in the first working mode. When the output power of the photovoltaic module is greater than the power required by the load, the DC-DC converter is in the second operating mode.

3. A photovoltaic power supply system according to claim 1 or 2, characterized in that, The first DC-DC conversion module includes: A first inductor module, wherein a first terminal of the first inductor module is electrically connected to the positive terminal of the photovoltaic module; A first switch module, wherein a first terminal of the first switch module is electrically connected to a second terminal of the first inductor module, and the second terminal of the first switch module is electrically connected to the negative terminal of the photovoltaic module and the negative terminal of the battery module; The fourth switch module has its first terminal electrically connected to the second terminal of the first inductor module, and its second terminal electrically connected to the positive terminal of the battery module. The third switch module has a first terminal electrically connected to the second terminal of the first inductor module, and the second terminal of the third switch module is electrically connected to the positive terminal of the load. Wherein, the first end of the first inductor module is the first end of the first DC-DC converter module, the second end of the third switch module is the second end of the first DC-DC converter module, the second end of the fourth switch module is the third end of the first DC-DC converter module, and the second end of the first switch module is the fourth end of the first DC-DC converter module.

4. A photovoltaic power supply system according to claim 3, characterized in that, The second DC-DC conversion module includes: The second switch module has its first terminal electrically connected to the positive terminal of the battery module. The fifth switch module has its second terminal electrically connected to the second terminal of the second switch module, and its first terminal electrically connected to the negative terminal of the battery module and the negative terminal of the load. The second inductor module has its first end electrically connected to the second end of the second switch module and the second end of the fifth switch module, and its second end electrically connected to the positive terminal of the load. Wherein, the first end of the second switch module is the first end of the second DC-DC converter module, the second end of the second inductor module is the second end of the second DC-DC converter module, and the first end of the fifth switch module is the third end of the second DC-DC converter module.

5. A photovoltaic power supply system according to claim 4, characterized in that, When the first DC-DC converter module is in the first state, the first DC-DC converter module repeatedly switches between mode one and mode two; When the first DC-DC converter module is in mode one, the first switch module is turned on, the fourth switch module is turned off, and the third switch module is turned off. When the first DC-DC converter module is in mode two, the first switch module is blocked, the fourth switch module is blocked, and the third switch module is turned on.

6. A photovoltaic power supply system according to claim 5, characterized in that, When the first DC-DC converter module is in the second state, the first DC-DC converter module cycles through mode one, mode two, and mode three in sequence; or, when the first DC-DC converter module is in the second state, the first DC-DC converter module cycles through mode one, mode two, mode three, and mode two in sequence. When the first DC-DC converter module is in mode three, the first switch module is blocked, the fourth switch module is turned on, and the third switch module is blocked.

7. A photovoltaic power supply system according to claim 6, characterized in that, include: The first filter module has its first end electrically connected to the positive terminal of the photovoltaic module and the first end of the first inductor module, and its second end electrically connected to the negative terminal of the photovoltaic module and the second end of the first switch module. The second filter module has its first end electrically connected to the second end of the fourth switch module and the positive terminal of the battery module, and its second end electrically connected to the second end of the first switch module and the negative terminal of the battery module. The third filter module has its first end electrically connected to the second end of the second inductor module and the positive terminal of the load, and its second end electrically connected to the first end of the fifth switch module and the negative input terminal of the load.

8. A photovoltaic power supply system according to claim 7, characterized in that, The first switching module includes a first MOSFET, the first terminal of which is electrically connected to the second terminal of the first inductor module, and the second terminal of which is electrically connected to the negative terminal of the photovoltaic module and the negative terminal of the battery module. The fourth switch module includes a fourth diode, the first end of which is electrically connected to the second end of the first inductor module, and the second end of which is electrically connected to the positive terminal of the battery module. The third switching module includes a third MOSFET and a sixth diode. The first terminal of the sixth diode is electrically connected to the second terminal of the first inductor module, the second terminal of the sixth diode is electrically connected to the first terminal of the third MOSFET, and the second terminal of the third MOSFET is electrically connected to the positive terminal of the load.

9. A photovoltaic power supply system according to claim 8, characterized in that, The voltage of the photovoltaic module and the voltage across the load terminals are both lower than the voltage of the battery module.

10. A photovoltaic power supply system according to claim 9, characterized in that, The second switching module includes a second MOSFET, the first terminal of which is electrically connected to the positive terminal of the battery module; The fifth switching module includes a fifth diode, the second end of which is electrically connected to the second end of the second MOS transistor, and the first end of which is electrically connected to the negative terminal of the battery module and the negative terminal of the load.

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