Working principle of lithium-ion battery energy storage power station
Emergency lithium-ion battery energy storage vehicles or megawatt-level stationary energy storage stations both operate by using inverters to directly convert high-power lithium-ion battery packs into single-phase or three-phase AC power. Normally, the battery packs can be charged at any time, and once fully charged, they can be readily accessed. Energy storage batteries are indispensable energy storage components in solar photovoltaic power generation systems. Their key function is to store the electrical energy of the photovoltaic system and provide power to the load during periods of insufficient sunlight, at night, and in emergency situations.
1. Charging
Emergency lithium-ion battery storage vehicles or megawatt-level stationary energy storage stations are equipped with both slow and fast charging ports. The fast and slow charging methods control the charging time by selecting different charging currents. The entire charging process is monitored by an intelligent management system; when the voltage of any single lithium-ion battery cell reaches a set value, the charger automatically stops charging the battery pack.
2. Discharge
Emergency energy storage vehicles or megawatt-level stationary energy storage stations are specially designed with output interfaces (generally, two types are designed according to user requirements: high-power three-phase output interface and conventional single-phase output socket).
3. Maintenance
Normally, you only need to check the parameters of each individual cell on the lithium-ion battery management system display screen; no manual maintenance is required. The battery management system features a visible capacity display, voltage display, and displays of the temperature and minimum or maximum voltage of each individual cell.
Application scenarios of lithium-ion battery energy storage power stations
Lithium-ion batteries for energy storage are gaining increasing attention as an emerging application scenario. Energy storage is one of the important means to address the intermittent fluctuations of new energy sources such as wind power and photovoltaics, and to achieve peak shaving and valley filling. In the practical application of lithium-ion battery energy storage in my country, renewable energy grid connection, user side, grid side, and ancillary services are the four most important areas.
1. Energy storage emergency power vehicle
The emergency energy storage vehicle consists of a lithium-ion battery pack, an inverter, and a battery management system. The inverter directly converts the battery power into single-phase or three-phase AC power. Normally, the battery pack can be charged at any time during designated charging periods. Once fully charged, the battery pack can be used at any time within one year, eliminating the need for float charging. We can supply 100kW, 1000kW, 5000kW, and megawatt-level mobile emergency energy storage vehicles. These vehicles can be used for national defense and military applications, civilian disaster relief, or power supply for large public events. They are fully charged during off-peak hours and are ready to be deployed to their destinations at any time.
2. Fixed energy storage power stations
A stationary energy storage power station consists of lithium-ion battery packs, a BMS management system, a PCS converter system, an EMS energy monitoring system, and auxiliary systems (including temperature control and fire protection), all installed within a container. Because lithium-ion batteries have low self-discharge, they do not need to be kept in a float-charge state for extended periods like traditional lead-acid, nickel-cadmium, or nickel-metal hydride batteries. Combined with a renewable energy generation system, the energy storage power station becomes a distributed power source within an independent microgrid. It is suitable for providing reliable power to areas without or lacking electricity, and can also provide peak shaving, valley filling, and frequency regulation services to the main power grid.
Battery energy storage power stations can be used in conjunction with distributed/centralized new energy power generation, which is one of the effective ways to solve the grid connection problem of new energy power generation. With the increasing scale of new energy power generation and the continuous development of lithium-ion battery energy storage technology, it will become a major key technology supporting my country's clean energy development strategy.
3. Backup power supply for communication
The telecommunications backup power market mainly comprises two parts: the incremental market each year consists of energy storage for newly built base stations, and the basic market volume each year consists of the replacement of batteries in existing base stations upon reaching maturity. my country Tower announced this year that it will no longer purchase lead-acid batteries. Considering that the scale of second-hand batteries is insufficient to meet demand, a concentrated demand for lithium battery replacement is expected around 2020. In addition, the construction of 50,000 to 100,000 new base stations annually will generate 1.2 to 2.4 GWh of lithium battery demand, totaling approximately 10 GWh of battery demand annually, which will be met by lithium iron ion batteries and second-hand batteries.
In summary, lithium-ion battery energy storage technology, with its advantages of high efficiency, application flexibility, and fast response speed, is gradually gaining an increasingly important position in the power energy storage market. Lithium-ion batteries can be applied to power quality, reliability control, backup power, peak shaving and valley filling, energy management, and renewable energy storage.
