What is Included in An Commercial Energy Storage System?

Commercial energy storage system is mainly used in peak shaving, photovoltaic self-consumption optimization, standby power, new energy vehicle charging stations and other scenarios, can coordinate the grid, photovoltaic, diesel generators and other hybrid energy, so what are the core components of such a complex energy storage system?

Batteries in Commercial Energy Storage Systems

The battery in an energy storage system is a key component that is used to store electrical energy. Battery systems of different capacities can be combined for different energy needs.

What should you know about battery packs in commercial energy storage systems?

Battery types: commonly used battery types in energy storage systems include lead-acid batteries, lithium-ion batteries (lithium iron phosphate-based), nickel-cadmium batteries, sodium-sulfur batteries, and so on. Each type of battery has its advantages and applicable scenarios.

Lithium-ion batteries: Lithium-ion batteries are one of the most common types of batteries for energy storage systems, widely used in portable devices, electric vehicles and home energy reserve systems. It is characterized by high energy density, light weight and long life.

Cycle life: The cycle life of a battery refers to the number of charge/discharge cycles that a battery is capable of. Cycle life is usually related to factors such as battery type, manufacturing process and usage conditions.

Capacity: The capacity of a battery indicates the amount of electrical energy it can store. Capacity is generally measured in ampere-hours (Ah) or kilowatt-hours (kWh). The capacity of an energy storage system depends on the total capacity of the connected battery packs.

Deep Discharge: Deep discharge is the level at which a battery is discharged below its rated capacity. The level of deep discharge is usually related to the design and manufacture of the battery and excessive deep discharge may shorten the life of the battery.

Charge/Discharge Efficiency: The charge/discharge efficiency of a battery indicates the extent to which electrical energy is lost during charging and discharging. Highly efficient batteries minimize energy loss during charging and discharging.

Battery Management System (BMS): A BMS is a device used to monitor and manage the battery. It monitors the battery's status, temperature, voltage and other parameters, and controls the charging and discharging process to optimize battery performance and extend life.

Safety: Battery safety is an important consideration. Certain battery types may be at risk of overcharging, over-discharging, overheating, etc., and therefore require appropriate safety measures, such as overcharging protection and temperature monitoring.

Environmental impact: Different types of batteries have different impacts on the environment. When considering energy storage systems, in addition to performance and economic factors, you also need to consider the environmental performance of the battery and recycling issues.

Cost: Battery cost is an important part of the overall cost of the energy storage system. With technological advances and scale effects, the cost of batteries is gradually decreasing.

PCS for Commercial Energy Storage Systems

The PCS (Power Conversion System) is a key component in an energy storage system that manages the conversion, scheduling and control of electrical energy.

What You Should Know About PCS in Commercial Energy Storage Systems?

Function: The main function of a PCS is to convert DC energy in an energy storage system to AC energy, as well as to convert AC energy from the grid or other generation sources to DC energy to meet the charging and discharging needs of the energy storage system.

Inverter and converter: A PCS typically includes an inverter and a converter. The inverter converts DC energy to AC energy, while the converter converts AC energy to DC energy.

Power Dispatch: PCS realizes the power dispatch of the energy storage system by controlling the flow of power and the frequency and voltage of the current. It can output power from the storage system to the grid or input power from the grid into the storage system.

Frequency and voltage regulation: PCS participates in the regulation of the grid frequency and voltage by adjusting the frequency and voltage of the output current to maintain the stable operation of the grid.

Capacity and power: The capacity and power of a PCS determines the amount of electrical energy and power level it can handle. The size of the energy storage system and the application scenario will influence the selection of the appropriate capacity and power of the PCS.

Grid Interconnection: The PCS enables the energy storage system to interconnect with the grid to provide flexible power dispatch and support smooth grid operation. It enables charging and discharging operations of the energy storage system by controlling the flow of current.

Power quality: PCS also needs to pay attention to the quality of power during the power conversion process to ensure that the output AC power meets the standards and requirements of the grid to avoid negative impacts on the grid.

Efficiency: The efficiency of the PCS is an important consideration. A highly efficient PCS can minimize the energy loss during the power conversion process and improve the overall efficiency of the storage system.

Safety: The PCS needs to have safety features, including overload protection, short circuit protection, temperature monitoring and other functions to ensure the safe operation of the system.

Communication and control: PCS is usually connected to the monitoring and control system of the energy storage system, and the monitoring and control of the system operation status is realized through the communication interface.

BMS in Commercial Energy Storage Systems

The BMS (Battery Management System) is a critical component of an energy storage system that monitors, manages and protects the performance of the battery pack.

What You Should Know About BMS in Energy Storage Systems?

Battery Monitoring: The BMS provides a real-time understanding of the battery's operating status by monitoring the battery's voltage, current, temperature and other parameters. This helps ensure proper operation of the battery pack and provides basic data for performance analysis.

Equalization control: The BMS is able to implement equalization control between individual cell units within the battery pack. This is to prevent differences between cells, ensure stable performance of the entire battery pack, and improve service life.

Charge and Discharge Control: The BMS is responsible for controlling the charging and discharging process of the batteries to ensure that it is carried out within the safe range and scheduling of charging and discharging of the batteries is carried out as needed.

Temperature Management: The operating temperature of the battery has a great impact on its performance and life span. the BMS monitors the temperature of the battery and takes measures, such as cooling or heating, when necessary to maintain a suitable operating temperature.

Condition Estimation: The BMS monitors and analyzes battery parameters to perform battery condition estimation, i.e., to estimate the battery's remaining lifespan, capacity, and health, etc., which helps to optimize the use and maintenance of the battery.

Safety Protection: The BMS has various safety functions, including overcharge protection, overdischarge protection, short circuit protection, etc., to prevent the battery pack from being overcharged, overdischarged or other abnormalities, and to ensure the safe operation of the system.

Communication interface: BMS is usually connected with other components of the energy storage system, such as PCS (Power Conversion System) and monitoring system, through communication interface to realize the coordination and control of the whole system.

Fault diagnosis: The BMS is capable of fault diagnosis, detecting abnormalities in the battery pack and providing measures such as alarms or automatic circuit disconnection to prevent further expansion of the fault.

Data recording and analysis: BMS records the battery operation data, which is essential for analyzing battery performance, developing maintenance plans and system optimization.

Compatibility: BMS needs to be compatible with different types and brands of batteries, and therefore has a certain degree of versatility and scalability.