WE-BMS Transformer for Battery Management Systems

LTSpice files

LT
LTSpice_WE-BMS (rev22a).zip
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815.4 KB

Characteristics

Test voltage of 6400 V_DC / 1 min.
Construction: reinforced insulation
Up to 1500 V_DC working voltage
Integrated filter chokes for common mode interference suppression
Supports serial daisy chain isoSPI and SPI
Available in different footprints
Versions with low profile
Operating temperature: -40 °C up to +125 °C

Applications

Energy Storage systems
Uninterrupted Power Supply (UPS)
E-bikes, E-scooters
Isolation of industrial interfaces

Products

Order Code	Datasheet	Downloads	Status	Ports	V_{T DC} (V (DC))	Working Voltage (V (DC))	Cr (mm)	L (mm)	W (mm)	H (mm)
74941300	SPEC	8 files EDA models: Components ZIP ALT Altium_WE-BMS (rev24a).IntLib \| 1.5 MB CDS Cadence_WE-BMS (rev24a).zip \| 8.2 MB EAG Eagle_WE-BMS (rev24a).lbr \| 104.4 KB CAD files ZIP 3D 3D_WE-BMS_74941300 (rev1).pdf \| 332.3 KB IGS IGS_WE-BMS_74941300 (rev1).igs \| 3.9 MB STP STP_WE-BMS_74941300 (rev1).stp \| 1.1 MB Electric models ZIP PSP PSpice_WE-BMS (rev22a).zip \| 393.4 KB S S-Parameter_74941300 (rev22a).s6p \| 1.1 MB Download all 8 files as zip archive ZIP	Active i\| Production is active. Expected lifetime: >10 years.	1	4300	1000	6	7.6	9.5	5.5
74941301	SPEC	8 files EDA models: Components ZIP ALT Altium_WE-BMS (rev24a).IntLib \| 1.5 MB CDS Cadence_WE-BMS (rev24a).zip \| 8.2 MB EAG Eagle_WE-BMS (rev24a).lbr \| 104.4 KB CAD files ZIP 3D 3D_WE-BMS_74941301 (rev1).pdf \| 327.5 KB IGS IGS_WE-BMS_74941301 (rev1).igs \| 3.9 MB STP STP_WE-BMS_74941301 (rev1).stp \| 1.1 MB Electric models ZIP PSP PSpice_WE-BMS (rev22a).zip \| 393.4 KB S S-Parameter_74941301 (rev22a).s4p \| 3.1 MB Download all 8 files as zip archive ZIP	Active i\| Production is active. Expected lifetime: >10 years.	1	4300	1000	5	7.6	9.5	5.5
74941302	SPEC	8 files EDA models: Components ZIP ALT Altium_WE-BMS (rev24a).IntLib \| 1.5 MB CDS Cadence_WE-BMS (rev24a).zip \| 8.2 MB EAG Eagle_WE-BMS (rev24a).lbr \| 104.4 KB CAD files ZIP 3D 3D_WE-BMS_74941302 (rev1).pdf \| 439.4 KB IGS IGS_WE-BMS_74941302 (rev1).igs \| 4.7 MB STP STP_WE-BMS_74941302 (rev1).stp \| 1.3 MB Electric models ZIP PSP PSpice_WE-BMS (rev22a).zip \| 393.4 KB S S-Parameter_74941302 (rev22a).s6p \| 1.1 MB Download all 8 files as zip archive ZIP	Active i\| Production is active. Expected lifetime: >10 years.	1	4300	1000	10	9.5	15.4	3.45
74942402	SPEC	6 files EDA models: Components ZIP ALT Altium_WE-BMS (rev24a).IntLib \| 1.5 MB CDS Cadence_WE-BMS (rev24a).zip \| 8.2 MB EAG Eagle_WE-BMS (rev24a).lbr \| 104.4 KB CAD files ZIP 3D 3D_WE-BMS_74942402 (rev1).pdf \| 246.1 KB IGS IGS_WE-BMS_74942402 (rev1).igs \| 2.8 MB STP STP_WE-BMS_74942402 (rev1).stp \| 863.1 KB Download all 6 files as zip archive ZIP	Active i\| Production is active. Expected lifetime: >10 years.	1	6400	1500	15	12.5	28	7.3
74942300	SPEC	8 files EDA models: Components ZIP ALT Altium_WE-BMS (rev24a).IntLib \| 1.5 MB CDS Cadence_WE-BMS (rev24a).zip \| 8.2 MB EAG Eagle_WE-BMS (rev24a).lbr \| 104.4 KB CAD files ZIP 3D 3D_WE-BMS_74942300 (rev1).pdf \| 718.8 KB IGS IGS_WE-BMS_74942300 (rev1).igs \| 8.9 MB STP STP_WE-BMS_74942300 (rev1).stp \| 2.5 MB Electric models ZIP PSP PSpice_WE-BMS (rev22a).zip \| 393.4 KB S S-Parameter_74942300 (rev22a).s6p \| 1.1 MB Download all 8 files as zip archive ZIP	Active i\| Production is active. Expected lifetime: >10 years.	2	4300	1000	10	15.1	14.7	4.75
74942301	SPEC	8 files EDA models: Components ZIP ALT Altium_WE-BMS (rev24a).IntLib \| 1.5 MB CDS Cadence_WE-BMS (rev24a).zip \| 8.2 MB EAG Eagle_WE-BMS (rev24a).lbr \| 104.4 KB CAD files ZIP 3D 3D_WE-BMS_74942301 (rev1).pdf \| 574.6 KB IGS IGS_WE-BMS_74942301 (rev1).igs \| 5.7 MB STP STP_WE-BMS_74942301 (rev1).stp \| 1.6 MB Electric models ZIP PSP PSpice_WE-BMS (rev22a).zip \| 393.4 KB S S-Parameter_74942301 (rev22a).s4p \| 3.1 MB Download all 8 files as zip archive ZIP	Active i\| Production is active. Expected lifetime: >10 years.	2	4300	1000	10	15.1	14.9	3.45
74942302	SPEC	8 files EDA models: Components ZIP ALT Altium_WE-BMS (rev24a).IntLib \| 1.5 MB CDS Cadence_WE-BMS (rev24a).zip \| 8.2 MB EAG Eagle_WE-BMS (rev24a).lbr \| 104.4 KB CAD files ZIP 3D 3D_WE-BMS_74942302 (rev1).pdf \| 594 KB IGS IGS_WE-BMS_74942302 (rev1).igs \| 6.3 MB STP STP_WE-BMS_74942302 (rev1).stp \| 1.7 MB Electric models ZIP PSP PSpice_WE-BMS (rev22a).zip \| 393.4 KB S S-Parameter_74942302 (rev22a).s6p \| 1.1 MB Download all 8 files as zip archive ZIP	Active i\| Production is active. Expected lifetime: >10 years.	2	4300	1000	10	15.1	15.4	3.45
74942400	SPEC	6 files EDA models: Components ZIP ALT Altium_WE-BMS (rev24a).IntLib \| 1.5 MB CDS Cadence_WE-BMS (rev24a).zip \| 8.2 MB EAG Eagle_WE-BMS (rev24a).lbr \| 104.4 KB CAD files ZIP 3D 3D_WE-BMS_74942400 (rev1).pdf \| 570.3 KB IGS IGS_WE-BMS_74942400 (rev1).igs \| 3.9 MB STP STP_WE-BMS_74942400 (rev1).stp \| 1.1 MB Download all 6 files as zip archive ZIP	Active i\| Production is active. Expected lifetime: >10 years.	2	6400	1500	15	15.45	27.85	4.85
74942401	SPEC	6 files EDA models: Components ZIP ALT Altium_WE-BMS (rev24a).IntLib \| 1.5 MB CDS Cadence_WE-BMS (rev24a).zip \| 8.2 MB EAG Eagle_WE-BMS (rev24a).lbr \| 104.4 KB CAD files ZIP 3D 3D_WE-BMS_74942401 (rev1).pdf \| 280.7 KB IGS IGS_WE-BMS_74942401 (rev1).igs \| 3.9 MB STP STP_WE-BMS_74942401 (rev1).stp \| 1.1 MB Download all 6 files as zip archive ZIP	Active i\| Production is active. Expected lifetime: >10 years.	2	6400	1500	15	15.45	27.85	4.85

	Order Code	Datasheet
	74941300	SPEC
	74941301	SPEC
	74941302	SPEC
	74942402	SPEC
	74942300	SPEC
	74942301	SPEC
	74942302	SPEC
	74942400	SPEC
	74942401	SPEC

Samples

	Order Code	Datasheet	Downloads	Status	Ports	V_{T DC} (V (DC))	Working Voltage (V (DC))	Cr (mm)	L (mm)	W (mm)	H (mm)	Samples

Transformer for Battery Management Systems with integrated Common Mode Choke

The WE-BMS series isolates the serial-connected components of the battery pack and the following BMS controllers from each other, suppressing any voltage differences and EMI that may occur. The design from Würth Elektronik provides a much larger physical creepage distance as opposed to other competitors, following market requirements for this kind of applications.

By maintaining the physical distance through the innovative design regardless of coated traces, high system safety and reliability can be achieved through special robustness against dryness or heat. Fully insulated wires are used for flat design and even better isolation properties.

Thanks to the innovative construction, a larger physical creepage distance can be achieved with the same size as with the conventional design.

The included transformers and common mode chokes ensure BMS isolation and suppresselectromagnetic interference for reliable signal transmission.

The WE-BMS series supports serial Daisy Chain, isoSPI, SPI and other signal isolations. Single and dual transformer for one or two channels are available.

BMS Layout Guidelines

The signal lines should be kept as short as possible and the transformer should be as close as possible to the isoSPI cable connector. A distance of <2 cm is suggested.

IC should be placed between 1-2 cm from the transformer to avoid magnetic coupling.

For four-layer or multilayer PCBs, the area around the BMS traces, the BMS socket and the transformer should be exposed in all layers. The distance around this area to copper surfaces and traces should be at least 4 mm, depending on the system working voltage.

From the smallest to the largest applications

The transformers with 1000 V<sub>DC</sub> working voltage are suitable for smaller energy storage systems such as consumer energy storage and for applications with lower voltages such as 600 V<sub>DC</sub> — The transformers with 1000 V_DC working voltage are suitable for smaller energy storage systems such as consumer energy storage and for applications with lower voltages such as 600 V_DC

BMS transformers with a working voltage of 1500 V<sub>DC</sub> and a test voltage of 6400 V<sub>DC</sub> are available for applications with large battery packs, such as in energy storage systems for solar and wind farms. — BMS transformers with a working voltage of 1500 V_DC and a test voltage of 6400 V_DC are available for applications with large battery packs, such as in energy storage systems for solar and wind farms.

What is a battery management system (BMS)?

A BMS is an electronic system that manages a rechargeable battery with the goal to make it safe and reliable.

Functions of a BMS:

Protecting the battery from operating outside its safe operation area
Monitoring its state of charge and state of health
Calculating secondary data and reporting that data
Controlling its environment
Authenticating it and/or balancing it

Why is a transformer needed in a BMS?

The individual cells in a battery pack are connected in series as well as the following BMS controllers. Between the components or PCBs connected in series, voltage differences and electromagnetic interference can occur. A transformer can be used to insolate the components from each other and suppress EMI interference. Therefore, WE-BMS transformer supports the BMS isolation and EMI noise suppression for a safe and reliable operation.

What is the partial discharge test?

Partial discharges are localized dielectric breakdowns. Fixed insulation in which partial discharges occur during operation is not permitted in the long term.

To ensure the long term reliability of the insulation, Würth Elektronik carries out the partial discharge test in accordance with IEC 60664-1.

The test is passed if the quantity of partial discharges is below a limit value of 10 pC (pico coulomb).

Transformer with or without center tap?

The Würth Elektronik product portfolio offers transformers with and without a center pin. In addition to the integrated common mode choke in the transformer module, the center pin contributes to the suppression of common mode interference. For this purpose, a bypass capacitor is connected to the center pin, which provides a low impedance ground connection for common mode interference and thus diverts it towards earth. This leads to an improvement in isoSPI performance. Please refer to the IC manufacturer's data sheet for the selection of capacitors.

Learn more

WE-BMS Transformer for Battery Management Systems
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