Bms insulation detection of energy storage system

What is a battery management system (BMS)?

BESS often consists of multiple battery racks arranged in a modular and scalable manner to meet the energy storage needs of a particular application. Each rack within a BESS typically includes a set of batteries, a battery management System (BMS), and associated hardware to facilitate energy storage, monitoring, and control.

What are the methods used for insulation monitoring in energy storage field?

Currently, the methods used for insulation monitoring in the energy storage field are mainly external resistance method and AC injection method. The AC current injection method generates a square wave signal which is then injected into the RC circuit between the HV line and the Protective Earth (PE) through an RC filter or transformer.

How to test an energy storage system?

The energy storage system's insulation resistance is typically tested using the existing BMS (Battery Management System) and its standards. The bridge method is employed for measurement, in conjunction with the PCS (energy storage converter) system. The insulation test principle of the entire energy storage system is shown in Figure 1-1.

What are the standards and principles of DC insulation test?

According to the Gb/T18384.1-2015 standard for on-board rechargeable energy storage systems, the BMS is required to conduct insulation tests on the integrated state of all components of the power lithium-ion battery system and use the insulation resistance value to calculate the insulation state.

What is an insulation monitoring device?

International standards demand that the leakage current must be limited to 10 mA, to avoid personal injury from contact with the system. The insulation monitoring device monitors this insulation resistance and initiates a shutdown in case the insulation resistance is not sufficient.

What are the common methods of insulation detection?

Principles of common methods for insulation detection: National standard method： The improved volt ampere method is used to measure the insulation resistance, that is, the reference resistance is used in parallel, and the insulation resistance is obtained through simple mathematical operation.