RT22 | Closed Loop Reconfigurable HIL Verification and Test System for Multi-Pack BMS System

I am going to present a programatically reconfigurable Closed loop BMS Hardware in Loop System based on OPAL-RT CMDE (Cell Monitoring Device Emulation) Solution. Traditionally Battery Management System HILs use expensive Cell Emulators which are connected in series to replicate the modules/busbars in the battery pack. The reconfiguration of cell emulators to create a new battery pack architecture is time consuming and prone to wiring errors. For this reason usually a dedicated BMS HIL system is used for each battery pack architecture. Another limitation of the Cell Emulator based approach is that the stack voltage can reach hundreds of volts which necessitates additional safety steps that must be taken for the isolation from low voltage components. Hence, I designed a multipack HIL setup using OPAL-RT CMDE solution. Each pack could have 2 to 16 AFEs(Analog Front End) devices depending on the application. The CMDE solution provides all the functionality of several AFE devices including balancing resistor functionality. An equivalent circuit model with two RC branches is used to represent the closed loop electrical behavior of the individual cells. It is modeled in MATLAB Simulink and compiled for NI Veristand RealTime Target. The model can run both in an open and closed loop model fulfilling various testing needs. The thermal behavior is modeled in matlab as well and parametrized by test data from the cells used. This HIL system has 4 Programmable High Voltage Power Supplies to simulate the Pack, Link and Precharge and Charging station voltages at various Open and Closed loop arrangements. Other components of the HIL system are the following; Isolation Resistance Emulator High Precision Shunt Current Sensor Emulator E-Load to emulate high current failure through the Contactor Coils