Solar power generation is more popular due to the advantages of cleanness, high efficiency, convenience, rapidness, simple system, wide applicable environment, high cost performance and the like, and various policies are continuously released from the country to the local to guide and support the development of the solar industry. Under the large background, the solar industry chain develops rapidly and orderly from upstream silicon material purification production, to midstream chip and module manufacturing, and to downstream solar system application, and the proportion of clean solar power occupied in the whole power application is higher and higher.
The solar power generation is direct current, and the solar power generation system is mostly composed of a power generation part, an inversion part and a power utilization part and can be divided into a grid-connected system, an off-grid system and a grid-connected and off-grid system according to the relation with a power grid. The grid-connected system is characterized in that direct current generated by the sun is converted into alternating current through a photovoltaic inverter, the alternating current is subjected to voltage adjustment through a transformer, and the alternating current is adjusted into electric power with the same voltage and frequency as a large power grid to be directly connected to the grid. The off-grid system needs to be provided with an energy storage system, and the energy storage system, the inverter, the controller, the transformer and the like form an optical storage off-grid system together to supply power for loads. The grid-connected and off-grid system has the functions of the two, can perform bidirectional interaction with a large power grid, and can be used for loading power from solar energy, an energy storage battery and the large power grid.
At present, more and more direct current electric appliances are used in various loads of household electric appliances, the direct current electric appliances are smaller than USB loads such as mobile phones, flashlights, LED lamps and bracelets, and the direct current electric appliances are larger than loads such as televisions, refrigerators, washing machines, electric bicycles and electric automobiles which can be directly connected with direct current, namely, alternating current conversion can be carried out without using adapters. Therefore, for the solar direct-current microgrid system, direct-current load access to the system is more efficient.
In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the drawings of the embodiments of the present invention are combined below to clearly and completely describe the technical solution of the embodiments of the present invention. It is to be understood that the embodiments described are only some of the embodiments of the present invention, and not all of them. All other embodiments, which can be obtained by a person skilled in the art without any inventive work based on the described embodiments of the present invention, belong to the protection scope of the present invention.
As shown in fig. 1, the utility model provides a direct current solar energy system, include: the solar energy component 1, the solar energy controller 2, at least one DC/DC voltage boosting circuit 3 and at least one DC/DC voltage reducing circuit 4;
the output end of the solar energy component 1 is electrically connected with the input end of at least one DC/DC boosting circuit 3 and at least one DC/DC voltage reducing circuit 4 through the solar energy controller 2.
The direct current solar energy system that this embodiment provided, from the electricity generation to the power consumption, need not convert the alternating current into, directly supply power for direct current load, have advantages such as the system is simple, energy loss is little, the whole efficient of system, and can satisfy the power consumption requirement of the load of different power demands simultaneously.
In this embodiment, the number of the DC/DC boost circuits 3 and the magnitude of the output voltage may be configured according to the actual power condition and the load condition of the solar module 1, because the number of the DC/DC boost circuits 3 is at least two, and the output voltages of the at least two DC/DC boost circuits 3 are different. The number of the DC/DC voltage reduction circuits 4 and the magnitude of the output voltage can be configured according to the actual power condition and the load condition of the solar module 1.
In this embodiment, the output interface is a standard interface with different voltage levels according to related standards, including but not limited to a 5V USB interface, an ATX 12V interface, an ATX 48V interface, and a charging interface of an electric vehicle with a maximum voltage of 750V. The plurality of interfaces can work independently and simultaneously, and the power distribution during simultaneous work can be controlled by the existing mature technology. The interface of the DC/DC booster circuit 3 for outputting voltage comprises one or more of a USB interface, an ATX interface and an electric vehicle charging interface. The interface of the voltage output by the DC/DC voltage reduction circuit 4 includes a USB interface and/or an ATX interface.
In another preferred embodiment, as shown in fig. 2, the DC solar system further includes a voltage stabilizing circuit 5, wherein the input end of the voltage stabilizing circuit 5 is electrically connected to the output ends of the DC/DC boost circuit 3 and the DC/DC buck circuit 4, respectively. In this embodiment, the voltage stabilizing circuit 5 is arranged to effectively improve the stability of the output voltage of the system, effectively protect the load, and improve the user experience.
In another preferred embodiment, as shown in fig. 3, the dc solar system further comprises an energy storage module 6, and the output end of the solar module 1 is electrically coupled with the input end of the energy storage module 6 through the solar controller 2. In this embodiment, the energy storage module 6 is arranged to store the surplus electric quantity except for the direct supply of the load power consumption in the power generated by the solar module 1, thereby effectively improving the utilization rate of the power generated by the solar module 1.
In another preferred embodiment, the output of the energy storage module 6 is electrically coupled to the input of the DC/DC boost circuit 3 and/or the input of the DC/DC buck circuit 4. In the present embodiment, the DC/DC boost circuit 3 and the DC/DC buck circuit 4 are collectively referred to as a DC/DC converter circuit 7. The energy storage module 6 is connected with the input end of the DC/DC booster circuit 3 and/or the DC/DC voltage reduction circuit 4, can generate electricity in a mode or in a mode that the solar component 1 cannot generate electricity in real time, and can provide electric energy for a load under the condition that the power demand of the load cannot be met, so that the power demand of a user is met.
In another preferred embodiment, as shown in fig. 4, the energy storage module 6 includes an energy storage battery 61 and a charge-discharge protection circuit 62, and the energy storage battery 61 is charged or discharged through the charge-discharge protection circuit 62. The charging and discharging protection circuit 62 can prevent the occurrence of the overcharge or overdischarge of the energy storage battery 61, effectively protect the energy storage battery 61, and prolong the service life of the energy storage battery 61.
In this embodiment, the energy storage battery 61 is not limited to a battery module formed by connecting lithium ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, and the like in series and in parallel, and the configuration capacity of the energy storage battery 61 is determined according to the load power, the standby power time, the input power of the solar module 1, and the like. In this embodiment, the charge and discharge protection circuit 62 can adopt a product BMS that is mature and general in the market and has a perfect battery management function to protect the energy storage battery 61, and the main functions of the BMS include acquisition and transmission of data such as current, voltage, temperature and the like of the energy storage battery 61, overpressure, overcurrent protection and the like of the energy storage battery 61.
In another embodiment, the solar controller 2 is a solar maximum power tracking controller for tracking the generating efficiency of the solar module 1, so that the solar module 1 is always at the optimal output power. The solar maximum power tracking controller is a mature technology in the market and is not described in detail.
It should be noted that the solar module 1 described in this embodiment includes, but is not limited to, a crystalline silicon series product and a thin film series product. Among them, the crystalline silicon series products include but are not limited to monocrystalline silicon and polycrystalline silicon solar cells; thin film series products include, but are not limited to, solar cells of amorphous silicon, cadmium telluride, gallium arsenide, copper indium gallium selenide, cadmium sulfide, perovskite, and the like.
The main application scenario of the direct current solar system provided by the embodiment is a household light storage off-grid scenario, and includes power supply of areas without a large power grid, such as household application, industrial and commercial application, and remote areas. The power of the solar component 1 is more than 1kW, and the output voltage of the system is between 5V and 750V, so that a plurality of common voltage gears are set.
When the day weather is good, the solar component 1 generates electricity and outputs total power PSWhile the loads consume the total power PLWhen P isS≥PLMeanwhile, the solar module 1 supplies power to the load and the energy storage battery 61 at the same time, the load is preferentially ensured to work, and the energy storage battery 61 is in a charging state; when P is presentS＜PLIn the meantime, the energy storage battery 61 and the solar module 1 supply power to the load at the same time, and the output power ratio can be automatically adjusted by using the existing mature technology.
At night, the solar module 1 stops generating power, and the power for the load is provided by the energy storage battery 61, so that the power required by the load in a period of time can be met.
The following are some more specific embodiments for illustrating an application scenario of the dc solar system provided in this embodiment.