SL1010A BMS Environment

SL1010A Scienlab BMS Environment

Solution Overview

As an established energy storage test system manufacturer, Keysight has a sound knowledge of Battery Management Systems (BMS) and batteries. Based on many years of engineering experience, Scienlab created a testing solution that leaves nothing to be desired.

SL1010A Scienlab BMS Environment

A BMS assumes important safety, control, and regulation functions. Those functions include monitoring parameters such as voltage, current, temperature, and state of charge (SOC). A BMS also regulates thermal management, energy management, cell balancing, and performance.

The modular system architecture enables individual compilation including ready-to-use cell models. It also enables flexible control of the system. The emulators are implemented by standardized interfaces into hardware-in-the-loop (HiL) environments such as Vector or dSpace.

The SL1010A Scienlab BMS Environment from Keysight enables you to test and improve all the above-mentioned functions of the BMS during the BMS development. Instead of real cells, Scienlab Cell Emulators are connected to emulate various cell types including ready-to-use cell models. The modular system architecture enables individual compilation and flexible control of the system. The emulators are implemented by standardized interfaces into HiL environments such as Vector or dSpace.

Fields of application

• Reproducible testing and optimization of the BMS
• Emulation of individual cells as well as modules and packs at cell level
• Validation of all BMS development steps with respect to hardware and software
• Testing of newly developed algorithms (balancing, SOC, SOH)
• Testing of fault cases (over-temperature, over-voltage, etc.)
• Tests with passive and active balancing circuits (Inductive and capacitive)
• Verification of measuring accuracy in various operating situations
• Validation of end products

Delivered documentation

• BMS Environment documentation:
• CE Declaration of conformity
• Operating instructions Scienlab BMS Environment
• Getting started Scienlab BMS Environment
• Circuit diagram
• Acceptance and calibration report
• Documentation of the Simulink Battery-HiL-Model (depending on the option)
• Documentation of graphical user interface (GUI) (depending on the option)

System Options

Cell emulator (CE) channels

SL1010A-803 Cell emulator (±5 A)                     

One cell emulator plug-in card includes two channels of two independent cell emulators. The dielectric strength of both channels to each other, to Protective Earth (PE) and to another plug-in card is 1 kV. The number of in-series connectable channels is limited by the sum of single-cell voltages (< 1 kV). The range of output voltages covers typical battery voltages and is prepared for new operation fields like cells with high voltages and chemistries.

The cell emulators have analog class AB amplifiers and allow a continuous and interruption-free transition between source and sink operation. To minimize internal power losses, the analog amplifier's positive and negative operation voltages are variable and operate depending on the output voltage.

Cell emulators feature a high-precision measurement technique with traceable calibration and guaranteed measurement accuracy within the specific operating- and temperature range. The maximum control deviation is identical to the specified systematic error (that means, the setting accuracy and the measuring accuracy are identical). Keysight recommends annual calibration. Calibration and adjustment are possible without removing the system from its installation. All system channels are synchronized via the internal data bus and all data logging and set-value outputs are synchronous.

By use of this measurement, signal processes alias effects will be avoided by pulsed balance systems and charges of short-term current pulses will be correctly acquired, also.

In addition to the current measurement, every cell emulator offers a positive and negative charge acquisition. This additional measured value could be used to determine e.g. the state of charge (SOC).

The output stage typically has a signal rise- and fall time of 20 µs. The small signal bandwidth is typical 1 MHz. A high bandwidth is necessary to emulate high-frequency current pulses, in combination with a low internal resistance it is needed to verify the active cell balance circuitry. Output stages with a lower bandwidth are not able to react to current load changes fast enough, this would result in dynamic voltage errors.

A rise-time of set-point changes is achieved in the software by connecting a dU/dt limiter. By this parametrization, you can choose different compromises between rise-time and over-swing.