With the rapid development of the energy storage system, if only use the Photovoltaic power supply is different from traditional power supply. Its output power changes dramatically with the change of light intensity, temperature and other environmental factors, and it is uncontrollable. Therefore, if photovoltaic power generation is to replace traditional energy to achieve large-scale grid connected power generation, its will impact on the grid system much.

As solar photovoltaic power generation has the characteristics of high output level in the short time at noon, low output level in other periods, and no output at night. The energy storage technology has the characteristics of realizing the time-space translation of electric energy. The battery energy storage system is configured for the photovoltaic power station to transfer the noon output of photovoltaic power to other periods, reducing the peak output of the power station and reducing light rejection.

In the working process of the battery battery energy storage system, the principle of minimizing the number of charges and discharges of the battery battery energy storage system is to extend the service life of the battery energy storage system. During the peak hours of photovoltaic power generation, control the charging of the battery battery energy storage system to cut the peak output of the photovoltaic power station. After the peak period of photovoltaic power generation, control the discharge of the 48V powerwall solar energy storage system. The discharge control of the battery energy storage system can help smooth the fluctuation of photovoltaic output and the peak regulation of the auxiliary system, this helps maximize the role of energy storage. According to the different functions of the energy storage discharge, the battery energy storage system can be divided into three working modes, peak clipping mode, peak clipping &suppression mode and peak clipping & transfer mode.

Working mode I: peak clipping

During the peak output period of the photovoltaic power station, the application goal is to control the charging of the battery battery energy storage system. After the peak output period of the photovoltaic power, and during the daytime output period of the photovoltaic power, the power amplification of the battery battery energy storage system will increase, then discharge to the lower limit of the SOE working range of the battery battery energy storage system, then the battery energy storage system stops working to ensure that the working time of the battery energy storage system is within the power generation time of the photovoltaic power station, It will not increase the working time of the photovoltaic power station and can reduce the impact on the work arrangement of the photovoltaic power station as the configuration of the battery energy storage system.

Working mode 2: peak clipping+flattening

During the peak output period of the photovoltaic power station, the charging of the battery energy storage system is controlled with peak shaving as the application goal. The output fluctuation of large-scale photovoltaic power plants can be divided into two categories: one is the slow change of the output of photovoltaic power plants, such as the periodic change of the output of photovoltaic power plants caused by the alternation of day and night; The other is the sudden change of the output of photovoltaic power station, such as the sudden drop of the output of photovoltaic power station caused by cloud cover. In the first round, the range of change was large, but the change was slow; The second type of change has unpredictability and suddenness. In serious cases, the output is reduced from full power to less than 30% of the rated value within 1~2s. After the peak period of photovoltaic output, control the discharge of the battery energy storage system to the lower limit of the SOE working range of the 48V powerwall solar energy storage system with the goal of smoothing the decline and fluctuation of the output of the photovoltaic power station during the alternation of day and night. If it has entered the night, when the output of the photovoltaic power station is reduced to 0, the SOE of the battery energy storage system is still greater than 0.2, control the battery energy storage system to discharge at the rated power and constant power until the SOE reaches 0.2, and then control the battery energy storage system to stop working.

Working mode 3: peak clipping+transfer

During the peak output period of the photovoltaic power station, the charging of the 48V powerwall solar energy storage system is controlled with peak shaving as the application goal. The output period of the photovoltaic power station is 8:30~18:30, and the evening peak of the load occurs between 18:00~22:00. The photovoltaic power station has basically no output during this period. The peak regulation of the system can be assisted by controlling the discharge of the battery battery energy storage system. In order to reduce the number of actions of the 48V powerwall solar energy storage system and simplify the operation of the 48V powerwall battery energy storage system, the 48V powerwall is controlled to discharge at a constant power, and the discharge is at the lower limit of the SOE working range of the battery energy storage system, then the battery energy storage system stops working.

With the increasing proportion of photovoltaic power generation system in the power grid, its impact on the power grid must be effectively treated to ensure the safety and reliability of power supply. The application of 48V battery energy storage system in photovoltaic power generation system can solve the problem of power supply imbalance in photovoltaic power generation system to meet the requirements of normal operation. 48V powerwall solar energy storage system is very important for the stable operation of photovoltaic power station. The 48V powerwall battery energy storage system not only ensures the stability and reliability of the system, but also is an effective way to solve dynamic power quality problems such as voltage pulse, inrush current, voltage sag and instantaneous power supply interruption. And for the 48V battery energy storage system working draft can refer below picture.

For 48V powerwall solar energy storage system home use, mainly with the off grid and hybrid energy storage. Battery and inverter solution according to the actually need to design. For more information, can check with www.pcenersys.com for more 48V powerwall and home use energy storage system projects information.