The portable solar lighting tower storage battery is charged through the charge and discharge controller, and the electric energy converted from light energy is stored. At night, the battery pack provides input power for the inverter. Through the function of the inverter, the DC power is converted into AC power, which is sent to the power distribution cabinet, and the power is supplied by the switching function of the power distribution cabinet. The discharge of the battery pack is controlled by the controller to ensure the normal use of the battery. The photovoltaic power station system should also have limited load protection and lightning protection devices to protect the system equipment from overload operation and lightning strikes, and maintain the safe use of system equipment. Solar energy→electrical energy→chemical energy→electrical energy→light energy.
Portable solar light tower is a solid-state device that realizes P-V conversion with unique electronic characteristics. In the vast areas without power grids, this device can conveniently realize lighting and power supply for users. In some developed countries, it can also complement the regional power grid. In China, the main research and production are small-scale solar power generation systems suitable for household lighting in areas without electricity.
The portable solar light tower cell and the storage battery form the power unit of the system, so the performance of the storage battery directly affects the working characteristics of the system.
(1) Battery unit: Due to technical and material reasons, the power generation of a single battery is very limited. A practical solar battery is a battery system composed of a single battery connected in series and parallel, called a battery module (array). A single battery is a silicon crystal diode. According to the electronic characteristics of semiconductor materials, when sunlight irradiates on the P-N junction composed of P-type and N-type homogeneous semiconductor materials with different conductivity types, under certain conditions , solar radiation is absorbed by semiconductor materials, generating non-equilibrium carriers, namely electrons and holes, in the conduction and valence bands. Same as the P-N junction barrier region, there is a strong built-in electrostatic field, so it can form a current density J, a short-circuit current Isc, and an open-circuit voltage Uoc under light. If the electrodes are drawn out on both sides of the built-in electric field and connected to the load, theoretically speaking, a loop formed by the P-N junction, the connecting circuit and the load will flow, and the solar cell module will realize the power to the load. P output.
(2) Electric energy storage unit: The direct current generated by the solar cell first enters the battery for storage, and the characteristics of the battery affect the working efficiency and characteristics of the system. Battery technology is very mature, but its capacity is affected by the terminal demand and sunshine time (power generation time). Therefore, the watt-hour capacity and the ampere-hour capacity of the battery are determined by the predetermined continuous sunshine-free time.
