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Composition And Electrical Safety Requirements Of LFP Battery Indoor Cabinet

Jan. 2023

Due to the advantages of high energy density, long cycle life, low self-discharge rate, no memory effect, and green environmental protection, lithium-ion batteries have been widely used in new energy fields such as intelligent micro-grid, wind, and solar power generation and electric vehicles.

The LFP Battery Indoor Cabinet was created to improve power output and range.

Below is the sample introduction to the composition and electrical safety requirements of the LFP Battery Indoor Cabinet.

Composition Of LFP Battery Indoor Cabinet

A single Battery Cabinet in the LFP Battery Indoor System typically consists of several Battery Packs and high-voltage boxes, as shown in Figure 2. Battery packs and high-voltage boxes are usually designed as drawers for easy installation and maintenance. The battery pack usually contains one or more battery modules and a battery monitoring unit, which is responsible for collecting the voltage and temperature of the cells in the battery pack and uploading them to the battery control unit; the high-voltage box usually contains the battery control unit, high-voltage insulation detection unit, current sensor, fuse, pre-charge resistance, contactor, and circuit breaker and other high-voltage components, which is responsible for real-time monitoring of the entire LFP battery indoor cabinet parameters, fault diagnosis, electrical protection, SOC/SOH estimation, insulation testing and data logging, and interacting with energy storage converters and energy monitoring systems through CAN and Ethernet communication.

LFP Battery Indoor Cabinet

It is important to note that

(1) The battery control unit, battery monitoring unit, and high-voltage insulation detection unit may be independent or may be integrated on a single circuit board to form a complete battery management system.

(2) The current battery management system can be divided into two levels of architecture and three levels of architecture, generally, a single battery cabinet requires only two levels of architecture, while multiple battery cabinets used in parallel need to use three levels of architecture (i.e. battery control unit and higher-level battery control module).

Electrical Safety Requirements Of LFP Battery Indoor Cabinet

Similar to information technology equipment and power electronics, the electrical safety design of the LFP Battery Indoor Cabinet should first be based on the system voltage, surge voltage, temporary overvoltage, and the pollution level of the environment in which the product is used, to confirm the required electrical clearance and creepage distance between the various isolation lines, as well as the required insulation resistance and dielectric strength of the insulation materials used.

GB/T 36276-2018 "Lithium-ion Battery for Electric Energy Storage" simply defines the insulation withstand voltage level of the system, and GB/T 34131 "Technical Specification for Lithium-ion Battery Management System for Electrochemical Energy Storage Power Station" also defines only the insulation withstand voltage level that the battery management system should meet, and does not further explain the electrical clearance and creepage distance that the structure, electrical and hardware design should follow.

NB/T 42091-2016 "Technical Specification for Lithium-ion Batteries for Electrochemical Energy Storage Power Plants" adds electrical clearance and creepage distance requirements but does not explain how to correct the electrical clearance and creepage distance based on altitude and environmental pollution levels.

UL 1973:2018 and UL60950-1:2007 cover the above requirements in full and also provide different requirements on whether the battery is connected to the grid by conduction.

Therefore, until the national and industry standards are improved, the electrical safety design of the LFP Battery Indoor Cabinet is recommended to be implemented by the developer with reference to the relevant UL standards, provided that the customer's requirements are met.

If you have more ideas about LFP Battery Indoor Cabinet, welcome to discuss them.