Solar energy resources are a renewable and clean energy source, and the use of solar photovoltaic power generation systems is not limited by geographical or altitude factors. Solar cells have the characteristics of simple operation and long service life. The structure of solar photovoltaic power supply systems is simple, convenient for installation and transportation, and solar photovoltaic power generation technology has good development prospects.
1.Main features
The household solar photovoltaic power supply system is a type of off grid photovoltaic power supply system, which consists of circuit protection, battery pack, controller, etc., forming a convenient solar photovoltaic power supply. This type of solar photovoltaic power supply is suitable for application in areas with a wide range of environmental conditions. If it is to be used in areas with high power rates and electricity consumption levels, a small and convenient solar photovoltaic power supply should be used; For areas with low power rates and consumption levels, household solar photovoltaic power systems are mainly used in daily life. For example, in areas with abundant solar energy resources, it is necessary to create a reasonable solar photovoltaic power generation system based on the actual characteristics of household users. This not only promotes the effective utilization of clean energy, reduces carbon emissions, but also reduces the electricity consumption rate.
2.Main components
2.1 Solar cell modules
The components of a solar photovoltaic power generation system are solar cells, but solar cells cannot be directly applied to the system.
A single solar cell not only has low mechanical strength, but is also prone to breakage. If exposed to air, it is also prone to some corrosion phenomena; Due to the influence of the size of the silicon wafer material itself, the power of a single battery is relatively small. So, to use a single solar cell in series and package it, it is not only necessary to achieve internal connection, but also to provide direct current to form an inseparable solar cell module.
In the construction form of household systems, in order to meet its relevant requirements, solar cell modules should follow several principles. Firstly, it is necessary to have strong mechanical properties, so that solar modules can be installed and used without impact and vibration. Moreover, it is necessary to achieve good electrical insulation and strong resistance to ultraviolet radiation to ensure its service life. Finally, utilizing different working voltages and output power wiring methods can not only promote reliable connections between solar cells, reduce efficiency losses in series, but also ensure the stability of actual usage costs.
2.2 Battery
In solar photovoltaic power generation systems, solar cells mainly convert solar energy into a type of direct current energy, and during this period, convert and store electrical energy into chemical energy in the form of batteries. For solar photovoltaic power systems, the storage device can ensure sufficient electrical energy to the load at any time and achieve stability in use, thereby ensuring the storage and regulation of electrical energy in the solar cell. In order to achieve the stability of solar energy system operation, as a storage form, batteries need to continuously perform the process from charging to discharging. If there is inadequate charging and discharging during the actual execution period, it will affect the use of household solar photovoltaic systems. Firstly, it is necessary to use batteries with cyclic discharge performance, long cycle life, and strong charging and discharging capabilities. Secondly, it is necessary to reduce maintenance and ensure good charging and discharging performance in low-temperature environments. Finally, because the charging and discharging characteristics are not sensitive enough to high temperatures and can achieve high energy efficiency, the initial operation form of charging and discharging should be prohibited to ensure a high cost-effectiveness.
2.3 Controller
The charge and discharge controller is a device that prevents overcharging and discharging of energy storage batteries in solar photovoltaic power systems. It can achieve automated operation and become the main core component of solar photovoltaic power generation systems. The controller distributes the output voltage and current, and can manage the energy, battery protection, and overall operation of the solar photovoltaic system. The charging and discharging controller in the household solar photovoltaic power supply system can not only protect against load short circuits, internal short circuits, backflow discharge, lightning strikes, etc., but also reasonably control the voltage damage phenomenon generated at both ends of the solar cell.
2.4 Inverter
Inverters mainly include DC inverters and AC inverters, which are the main devices for converting DC to AC power. In various household appliances in our country, 220 V, 50 Hz AC power is used, and low-voltage DC power of 12 V, 24 V, and 48 V is used for batteries. They are all 220 V AC power output through exchangers and are widely used in various fields. To study inverters in household photovoltaic power generation systems, it is not only necessary to analyze the technical indicators related to voltage variation range, voltage output frequency, static current, etc., but also to analyze the load capacity, protection capacity, and insulation capacity of inverters. For example, during the confirmation of the rated values of input voltage and output power, if the ambient temperature is set to 25 ℃, the inverter will operate continuously. Moreover, it can not only protect against overcurrent, short circuits, and lightning strikes, but also ensure the stability and safety of relevant personnel during operation. It is also necessary to control the insulation resistance between the DC input, AC input, and the casing of the inverter at corresponding values.
3. System design
The main methods for designing household solar photovoltaic power sources are shown in Figure . Although there are few components in solar photovoltaic systems, in order to maximize the effectiveness of solar photovoltaic power generation systems, it is necessary to effectively grasp the radiation parameters of solar energy and the electricity demand of users, in order to achieve optimized design of various component parameters. So during the execution, the following analysis principles should be followed to promote the standardization of design work.
3.1 Configuration principles
The design of a typical household solar photovoltaic power generation system is intended for fixed use, but due to the low efficiency of the application of solar photovoltaic power generation products, during the configuration of the solar photovoltaic power generation system, it is not only necessary to ensure the overall firmness and reduce the degree of external damage, but also to promote the simple installation of components in maintenance and repair, thereby achieving strong universality of the product.
3.2 Electricity demand
In the design process of solar photovoltaic power generation systems, relevant factors such as electricity load, load nature, usage time, and power supply guarantee rate should be considered. Firstly, analyze the types of users, as the cost of solar photovoltaic power generation systems is relatively high. During the configuration period, classify the electricity demand based on usage time and power supply guarantee rate, and finally make targeted choices for relevant design schemes. Secondly, the analysis of load characteristics. During the selection of solar photovoltaic power generation systems and system equipment, it is necessary to analyze the load characteristics. The forms generated in the load mainly include DC load, AC load, etc. Thirdly, calculate the solar radiation energy resources, as solar radiation varies seasonally and also has different forms. The design of a household solar radiation photovoltaic power generation system is based on the annual radiation situation. If the radiation value of the difference in sunlight throughout the year is not utilized, the use of the system during the design period will increase costs, resulting in the inability to meet reasonable supply and demand in long-term power generation.
3.3 Capacity design
During the design of solar photovoltaic power generation systems, it is necessary to calculate the capacity of the solar cell components, batteries, and inverters in the system. Due to the significant relationship between solar cell components and the power generation of the system, the capacity of the inverter is determined based on the total power of the load and the type of load, while the capacity of the battery effectively ensures the depth of discharge based on the number of charges. When designing capacity, it is not only necessary to analyze the changes in load demand, meet the reliability of user electricity consumption, reduce the use of batteries, but also to improve economy and avoid the reduction of battery capacity.
4. Conclusion
With the continuous improvement of solar photovoltaic power generation efficiency and the continuous reduction of power generation costs, solar photovoltaic power generation technology has been applied to households. Using solar energy resources in various regions can not only achieve energy conservation and emission reduction, but also promote the effective utilization of clean energy.