Operational principle

The ESB-series outdoor base station system utilizes solar energy and diesel engines to achieve uninterrupted off grid power supply. Solar power generation is the use of photovoltaic panels to convert solar energy into electrical energy -48V DC, and then stabilize the load power supply through photovoltaic MPPT modules while charging the battery. When continuous rainy days cause low voltage in the battery, the starting oil engine supplies power to the load and charges the battery through a rectifier module. The management of centralized monitoring of urban electricity can achieve intelligent energy storage for peak shaving and valley filling through rectification modules, and operate according to the difference in peak valley electricity prices by discharging during the day and charging at night;

A. Under normal circumstances, the power supply system operates in a parallel float charging state, where the rectifier module, solar module, load, and battery work in parallel; In addition to supplying power to communication equipment, solar modules and rectifier modules also provide floating charging current for batteries.

B. Under normal circumstances, solar and mains power supply is normal, and the system output load and battery charging current are provided by the solar module. If the output power of the solar module is insufficient to provide all loads, it is supplemented by the rectifier module to maintain the normal operation of the communication equipment.

C. When the output mains power is cut off, the rectifier module stops working and the solar energy supplies power normally. The system output load and battery charging current are provided by the solar module. If the output power of the solar module is not enough to provide all loads, it is supplemented by the battery to maintain the normal operation of the communication equipment.

D. When the output mains power is cut off, the rectifier module stops working, and the solar energy cannot supply power normally. The system output load is powered by the battery to maintain the normal operation of communication equipment. When the battery is discharged for a period of time and meets the conditions for starting the diesel engine, the monitoring unit sends a signal to start the oil engine. After the oil engine is working normally, it can provide AC input power to the rectifier module, which will re supply power to the communication equipment and charge the battery to supplement the consumed electricity. When the conditions for stopping the oil engine are met, the monitoring unit sends a signal to stop the oil engine, and the oil engine shuts down.

E. The monitoring unit adopts a centralized monitoring method to manage solar power distribution, AC mains power distribution, DC power distribution, and oil engine functions. At the same time, it receives operational information from the rectifier module and solar module through CAN communication and performs corresponding control. The monitoring also has monitoring functions such as battery management, load discharge protection, battery protection, signal acquisition and alarm, and can perform backend communication. The monitoring unit can also connect to the local computer through RS485 or TCP network cable direct connection.

System composition

A. MPPT Photovoltaic Module: The Maximum Power Point Tracking (MPPT) system is an electrical system that adjusts the working status of electrical modules to enable photovoltaic panels to output more electricity. The system can effectively store the direct current generated by solar panels in the battery, which can effectively solve the problem of living and industrial electricity in remote areas and tourist areas that cannot be covered by conventional power grids, without generating environmental pollution.

B. Rectification module: High frequency switch rectifier, also known as no power frequency transformer rectifier, is a power module that converts AC input into DC output. In communication power supplies, also known as switch rectifiers, they generally provide DC power with a voltage of -48V. After distribution, a voltage of -48VDC can be obtained.

C. Monitoring module: Real time detection of the power generation voltage of the solar panel, and tracking of the highest voltage and current value (VI), a monitoring device for automatic charging and discharging of the battery. When the battery is fully charged, it will automatically cut off the charging circuit or convert charging to float charging, so that the battery does not overcharge. When the battery is over discharged, it will promptly issue an alarm prompt and relevant protective actions, This ensures that the battery can operate reliably for a long time. When the battery level is restored, the system automatically returns to normal state. In areas with particularly low temperatures, it also has a temperature compensation function.

D. Photovoltaic modules: This is the most core part of solar photovoltaic power generation systems, and its main function is to convert solar photons into electrical energy, thereby driving the load to work. The battery panel is divided into single crystal and polycrystalline.

E. Battery pack: It mainly stores the electrical energy converted from solar panels. Generally, it is a valve controlled maintenance free lead-acid battery. In low-temperature areas, solar gel batteries are needed and can be reused multiple times.

F. Inverter: can provide 220V and 110V AC power supply according to equipment requirements.

G. Photovoltaic bracket: The unique design structure of the solar bracket allows the components to have adjustable angles according to different regions, thereby fully utilizing local solar resources and achieving a power generation efficiency of 99.5%. At the same time, a detailed analysis and practice of the connection method, material selection, and support load analysis of photovoltaic modules are carried out to make them have good physical properties such as earthquake resistance, wind resistance, snow pressure resistance, corrosion resistance, theft prevention, etc., making photovoltaic modules applicable in a wider range of regions.