Modern battery storage systems have a high-voltage section for power transmission and a low-voltage section for battery management. Both must be galvanically isolated from each other, but still work together smoothly. WE-BMS transformers are used at the interface.
Battery storage is also becoming increasingly important on a large scale, for example for electric cars, but also as a buffer for renewable energies that fluctuate in their availability. However, energy storage systems, such as lithium-ion batteries, cannot simply be connected to a charging voltage or a consumer. Smooth operation requires sensors on the battery that measure the current, voltage, and temperature, as well as control electronics that prevent the valuable energy storage device from being charged or discharged outside of its specifications.
In a battery pack, the individual battery cells are connected in series, as are the associated BMS controllers. Voltage differences and electromagnetic interference can occur between the components or circuit boards. Transformers are used to isolate the components on the high and low voltage sides from each other and to filter out electromagnetic interference. They ensure that no dangerous voltages are transmitted to touchable parts or the BMS.
The WE-BMS transformers from Würth Elektronik have reinforced insulation in accordance with IEC 60664-1 and IEC 62368-1. They ensure reliable electrical isolation, i.e. there is no direct electrical connection between the connected high and low voltage levels. The operating voltage of the latest addition to the range of WE-BMS transformers has been increased from 1000 to 1500 VDC. The test voltage has also been increased from 4300 to 6400 VDC. The transformers are specified for an operating temperature of -40 to +125 °C and are certified according to the UL standard UL 62368-1 in document E507007.
Compared to other competitors, Würth Elektronik's design offers a significantly greater physical creepage distance, which is the shortest distance along the surface of an insulating material between two conductive parts.
As with most components from Würth Elektronik, there are also specific layout guidelines for the WE-BMS Transformer.
