I have a store in the comic world

Update as soon as possible!No ads!

To control the excitation current, you can control the magnetic field strength, control the power generation voltage and current.

Since the generator rotor has a small amount of residual magnetism even if there is no current flowing through the coil, as long as it is running, even if the stator emits a little electricity, it can slowly build up the voltage and then build up the current to run. If it is a new unit or a little leftover If the magnet is gone, you can connect an external power supply for excitation, and then switch to self-excitation after the voltage is established.

So whether to choose a generator?

The hunter thought for a few seconds, then put the matter aside, and turned his attention to the remaining four types.

What about solar cells?

The reason why the hunter thinks of solar cells is because the hunter has a solar cell on his body. Before setting off, the owner accidentally heard that the miniaturization technology of solar cells was mature, so he asked the hunter to get one.

It is a pity that this solar cell was used by Zhou Wenwen, and the power in the battery was quickly used up, and Zhou Wenwen was disgusted.

A solar cell is an optoelectronic semiconductor sheet that uses sunlight to directly generate electricity. It is also called a "solar chip" or a "photovoltaic cell." As long as it is exposed to illumination that meets certain illumination conditions, it can instantly output voltage and provide a loop. Generate electric current.

Solar cells are physically called solar photovoltaic, abbreviated as PV, or photovoltaic for short.

Solar cells are devices that directly convert light energy into electrical energy through the photoelectric effect or photochemical effect.

Crystalline silicon solar cells that work with the photovoltaic effect are the mainstream, but the implementation of solar cells with thin-film cells that work with the photochemical effect is still in its infancy.

A solar cell is a photovoltaic component that can convert energy. Its basic structure is formed by joining P-type and N-type semiconductors.

The most basic material of semiconductors is "silicon", which is non-conductive.

But if different impurities are doped into the semiconductor, it can be made into P-type and N-type semiconductors, and then the potential difference between the P-type semiconductor having a hole and the N-type semiconductor having an extra free electron is used to generate current.

Therefore, when sunlight illuminates, the light energy excites the electrons in the silicon atoms, resulting in convection of electrons and holes. These electrons and holes are affected by the built-in potential and are attracted to N-type and P-type semiconductors respectively. , while gathering at both ends.

At this time, if the outside is connected with electrodes, a loop is formed. This is the principle of solar cell power generation.

Simply put, the power generation principle of solar photovoltaics is a power generation method that uses solar cells to absorb sunlight with a wavelength of 0.4mm to 1.1mm and directly convert the light energy into electrical energy output.

Since the electricity generated by solar cells is direct current, if you need to provide power to household appliances or various electrical appliances, you need to install a DC-to-AC converter to convert it into alternating current to supply household or industrial electricity.

Charging Development of Solar Cells Solar cells are used in consumer goods, and most of them have charging problems. In the past, nickel-metal hydride or nickel-cadmium dry batteries were generally used for charging. However, nickel-metal hydride dry batteries cannot withstand high temperatures, and nickel-cadmium dry batteries have environmental pollution problems.

Supercapacitors are developing rapidly, with large capacity, shrinking area, and low price. Therefore, some solar products have begun to use supercapacitors as charging objects, thus improving many problems of solar charging:

Charging is faster, the life is more than 5 times longer, the charging temperature range is wider, and the usage of solar cells is reduced.

There are two methods of solar power generation, one is the light-heat-electricity conversion method, and the other is the light-electricity direct conversion method.

The light-heat-electricity conversion method generates electricity by utilizing the thermal energy generated by solar radiation. Generally, a solar collector converts the absorbed thermal energy into steam as a working fluid, and then drives a steam turbine to generate electricity.

The former process is a light-heat conversion process; the latter process is a heat-electricity conversion process, which is the same as ordinary thermal power generation.

However, the disadvantages of solar thermal power generation are that the efficiency is very low and the cost is high. It is estimated that its investment is at least 5 to 10 times more expensive than ordinary thermal power plants.

一座1000MW的太阳能热电站需要投资20～25亿美元，平均1kW的投资为2000～2500美元。

Therefore, it can only be used on a small scale for special occasions, and large-scale utilization is economically uneconomical and cannot compete with ordinary thermal power plants or nuclear power plants.

Direct light-to-electricity conversion is based on the photoelectric properties of specific materials.

Black bodies radiate electromagnetic waves of different wavelengths, such as infrared, ultraviolet, visible light, etc.

When these rays shine on different conductors or semiconductors, the photons interact with free electrons in the conductors or semiconductors to produce an electric current.

The shorter the wavelength and the higher the frequency of the ray, the higher the energy it has. For example, the energy of ultraviolet rays is much higher than that of infrared rays.

However, not all wavelengths of ray energy can be converted into electrical energy. It is worth noting that the photovoltaic effect has nothing to do with the intensity of the ray. Only when the frequency reaches or exceeds the threshold that can produce the photovoltaic effect, the current can be generated.

The maximum wavelength of light that can produce a photovoltaic effect in a semiconductor is related to the bandgap width of the semiconductor. For example, the bandgap width of crystalline silicon is about 1.155eV at room temperature. Therefore, light with a wavelength less than 1100nm is required to produce a photovoltaic effect in crystalline silicon. .

Solar cell power generation is a renewable and environmentally friendly way of generating electricity. During the power generation process, no greenhouse gases such as carbon dioxide are produced and no pollution is caused to the environment.

According to their production materials, they are divided into silicon-based semiconductor batteries, CdTe thin film batteries, CIGS thin film batteries, dye-sensitized thin film batteries, organic material batteries, etc.

Silicon batteries are divided into monocrystalline batteries, polycrystalline batteries and amorphous silicon thin film batteries.

The most important parameter for solar cells is conversion efficiency. Among the silicon-based solar cells developed in the laboratory, the efficiency of monocrystalline silicon cells is 25.0%, the efficiency of polycrystalline silicon cells is 20.4%, and the efficiency of CIGS thin-film cells reaches 19.6%. The efficiency of CdTe thin film cells reaches 16.7%, and the efficiency of amorphous silicon thin film cells is 10.1%.

Solar cell module composition and functions of each part:

1. The role of tempered glass is to protect the main body of power generation. There are requirements for its selection of light transmittance: the light transmittance must be high and it must be ultra-white tempered.

2. EVA is used to bond and fix the tempered glass and the main body of the power generation. The quality of the transparent EVA material directly affects the life of the component. EVA exposed to the air is prone to aging and yellowing, thus affecting the light transmittance of the component and thus affecting the durability of the component. The quality of power generation is in addition to the quality of EVA itself.

Chapter 0236 Preview of Solar Cells