Battery Management Systems (BMS) typically employ a three-level architecture (subordinate control, main control, and master control) to manage and control battery modules, clusters, and stacks. Below is a brief introduction to the three-level architecture of a BMS system.
First Level: Battery Management Unit (Subordinate Control)
The first level is the Battery Management Unit (BMU), also known as the Energy Storage Battery Management Module (ESBMM) or Cell Supervision Unit (CSU), depending on the manufacturer. This level primarily focuses on the collection of individual cell voltages and temperatures and executing battery balancing strategies. Data collected by the BMU is communicated to the second level via communication links, typically using CAN or daisy chain communication methods.
Second Level: Battery Cluster Management Unit (Main Control)
The second level is the Battery Cluster Management Unit (BCU) or Energy Storage Battery Cluster Module (ESBCM). This unit is responsible for collecting voltage, current, and insulation information of the battery cluster, controlling the contactors for battery protection, gathering information from the first-level BMU, and estimating battery state (SoX). The data collected by the BCU is communicated to the third level via communication links, usually employing CAN or Ethernet.
Third Level: BMS System Management Host or Stack-Level Management Unit (Master Control)
The third level is the BMS System Management Host or Stack-Level Management Unit, also referred to as Battery Stack Management Unit (BSU), Energy System Management Unit (ESMU), Battery Array Management System (BAMS), or Battery Array Unit (BAU). This level's primary functions include collecting information transmitted from the second-level BCU, storing and displaying data, providing real-time alarms, controlling the main circuit breaker, and offering contact feedback. It also ensures real-time communication with the Power Conversion System (PCS), Energy Management System (EMS), and local monitoring systems.
