Household solar photovoltaic power generation system composition and characteristics of detail
Solar power is divided into thermal power generation and photovoltaic power generation. Regardless of production and sales, development speed and prospects, solar thermal power generation can not catch up with photovoltaic power generation. May be due to the widespread popularity of photovoltaic power generation and less exposure to thermal power generation, usually the folk solar power generation often refers to solar photovoltaic power generation, referred to as photoelectric.
Household solar power generation system consists of solar cell, solar controller, battery (group). If the output power is 220V ac or 110V ac, an inverter needs to be configured.
Solar panel is the core part of solar power generation system, the role of solar panel is to convert the sun's light energy into electric energy, output direct current into storage battery. Solar panel is one of the most important components in solar power generation system. Its conversion rate and service life are important factors to determine whether solar cell has use value. Module design: designed according to IEC: 1215:1993 standard, 36 or 72 polycrystalline silicon solar cells are connected in series to form 12V and 24V modules. The module can be used in various household PHOTOVOLTAIC systems, independent photovoltaic power stations and grid-connected photovoltaic power stations, etc.
Features of solar panel raw materials:
Battery: high efficiency (more than 16.5%) monocrystalline silicon solar panels package, ensure sufficient power generation of solar panels.
Glass: low iron tempered suede glass (also known as white glass), thickness of 3.2mm, in the wavelength range of solar cell spectral response (320-1100nm) transmittance of 91% or more, for infrared light greater than 1200 nm has a high reflectivity. This glass at the same time can withstand the radiation of ultraviolet rays of the sun, transmittance does not drop.
EVA: the high quality EVA film with thickness of 0.78mm with anti-UV agent, antioxidant and curing agent is used as the sealant of solar cell and the connecting agent between glass and TPT. It has high light transmittance and anti-aging ability.
TPT: the back cover of the solar cell - fluorine plastic film is white, reflecting the sunlight, so the efficiency of the component is slightly improved, and because of its high infrared emissivity, but also can reduce the working temperature of the component, but also conducive to improving the efficiency of the component. Of course, the fluorine plastic film first has the basic requirements of aging resistance, corrosion resistance and air permeability required by solar cell packaging materials.
Frame: the aluminum alloy frame has high strength and strong resistance to mechanical impact. It is also the most valuable part of household solar power generation.
Two, solar controller
Solar controller is composed of special processor CPU, electronic components, display, switching power tube and so on.
Main features of solar controller:
1, the use of single-chip microcomputer and special software, to achieve intelligent control;
2. Accurate discharge control using battery discharge rate characteristic correction. Discharge terminal voltage is a control point modified by discharge rate curve, which eliminates the inaccuracy of simple voltage control over discharge and conforms to the inherent characteristics of battery, that is, different discharge rates have different terminal voltages.
3, with overcharge, overdischarge, electronic short circuit, overload protection, unique anti-reverse connection protection and other automatic control; The above protection does not damage any parts and does not burn safety;
4, the use of the series PWM charging circuit, the voltage loss of the charging circuit is reduced by nearly half compared with the use of diode charging circuit, charging efficiency is 3%-6% higher than non-PWM, increasing the use of electricity time; Overdischarge recovery of lifting charge, normal direct charge, float charge automatic control mode to make the system by longer service life; At the same time with high precision temperature compensation;
5, intuitive LED light emitting tube indicates the current battery state, so that users understand the use of the situation;
6, all the control adopts industrial chip (only with I industrial controller), can operate freely in cold, high temperature and humid environment. At the same time the crystal oscillator timing control, timing control is accurate.
7, cancel the potentiometer adjustment control set point, and use the E side memory to record the working control points, so that the setting is digitized, eliminate the control point error due to the potentiometer vibration bias, temperature drift and other factors to reduce the accuracy and reliability;
8, the use of digital LED display and Settings, one-click operation can complete all the Settings, the use of extremely convenient and intuitive role is to control the working state of the whole system, and the battery over charge protection, over discharge protection. Where the temperature difference is large, the qualified controller should also have the function of temperature compensation. Other additional functions such as light control switch, time control switch should be optional controller;
Batteries are used to store the electricity generated by solar panels during periods of light and release it when needed. Solar battery is "battery" in the application of solar photovoltaic power generation, the use of lead acid maintenance free battery, ordinary lead acid battery, colloidal battery and alkaline nickel cadmium battery four. Domestic widely used solar battery is mainly: lead acid free maintenance battery and colloidal battery, these two types of battery, because of its inherent "free" maintenance characteristics and the characteristics of less pollution to the environment, very suitable for reliable performance of the solar power supply system, especially unattended workstation.
The direct output of solar energy is generally 12VDC, 24VDC, 48VDC. In order to provide power to 220VAC appliances, it is necessary to convert the direct current power produced by the solar power generation system into AC power, so a DC-AC inverter is needed.