Solar cell system solution

Background of battery development: With the development of technology and social progress, solar specific lithium batteries have emerged. The power system must ensure safety and ensure stable operation and ultra-high safety of the battery during high-altitude movement and high current discharge.

The lithium battery design scheme adopts high-quality lithium iron phosphate cells, industrial grade inverter modules, and BMS management system. The BMS management system adopts imported chip design, and the battery has complete multiple protection design, accurate single string battery voltage detection, efficient active balancing management scheme, intelligent management of multiple string lithium batteries, and other advantages, effectively extending the battery life, with high reliability and high intelligence characteristics.

This power supply can also be used to power outdoor emergency communication equipment, as well as to power mobile radio wave exploration systems and other emergency equipment in the field. The system can output AC/220V AC power through both automotive power generation and battery power supply. The entire system includes lithium batteries, BMS (Battery Management System), battery status display screen, inverter system, charger, and military grade chassis for shock and drop resistance.

1、 Design requirements:

Design intelligent lithium batteries that match the host according to product specifications and customer requirements, integrating high specification safety performance, high-efficiency automatic balancing management, intelligent battery pack management, outstanding cycle life, and other functions into the solution.

2、 Design scheme for industrial portable emergency power supply:

1) Protection board (PCM): a protection circuit designed for lithium iron phosphate battery packs, designed to protect against the chemical characteristics of lithium iron phosphate batteries themselves, in addition to conventional overcharge, overdischarge, overcurrent, short circuit, and overheating protection; It also provides battery level detection and dynamic balancing of the entire battery pack.

2) Protection circuit: Imported ICs and MOS transistors are used for online real-time monitoring of battery cells for overcharging, overdischarging, overcurrent, short circuit, and other functions. Intelligent management solutions can maximize battery capacity and cycle life.

3) Overcurrent fuse: mainly designed for BMS protection failure. Due to the use of high-capacity and high-power battery cells in the scheme, although PMC has overcurrent and short-circuit protection, any abnormality can also cause the protection function to fail. In the event of an output short circuit, a very large current will be generated, leading to danger. Therefore, an overcurrent fuse is added to the scheme. When an abnormal short circuit occurs, the fuse will disconnect the circuit and cannot be restored, achieving the purpose of abnormal protection.

4) Battery cell: LARGE26650/3.2V/3000mAh lithium iron phosphate battery cells are used, with high consistency, high safety, and a cycle life of up to 2000 times for individual cells. The overall battery parameters are 12.8V/60Ah.

5) Current design: The normal operating current of the entire battery pack is 20A, with a maximum operating current of 30A and an instantaneous starting current of 60A.

6) Efficient active balancing, low-power 60mA balancing current, equivalent to 1.5A balancing effect.

7) A dedicated battery design display screen that can monitor battery usage in real-time.

8) The battery pack is isolated and fixed with plastic brackets, which is more conducive to battery heat dissipation and safe use.