Power modules save space in H/EVs

Electrifying existing cars imposes space constraints. The inverter has to be small to be placed in the cramped engine compartment. Inverter size is defined by the power modules used, which have to be small yet provide sufficient power to actuate the electric drivetrain. The size of a power module, however is defined by the power consumption of the power chips used inside, and the ability to cool these chips to stay below a maximum junction temperature.

The HybridPack Double Sided Cooling (DSC) power modules for H/EVs measure 42 x 42.4 x 4.77mm. They target HEV applications such as main inverters and generators with a typical power range of 40 to 50kW. They can be used in parallel configurations to support higher power.

Inductance is only 15nH, while blocking voltage was increased to 700V. Both factors support the development of inverter systems with reduced switching losses of about 25% and high efficiency, says the company. Integrated isolation allows the module to be directly attached to a cooler without external isolation. Each integrated IGBT chip is equipped with an on-chip current sensor for over-current protection. An on-chip temperature sensor provides derating and fast shut-off in case of over-temperature. The direct and precise sensing improves system monitoring. It also helps to simplify the functional safety architecture of automotive system suppliers and car manufacturers, says the company.

By combining double sided chip cooling with electrical isolation of the heatsinks, the thermal resistance R _thJC of the HybridPack DSC is reduced to 0.1Kelvin/W.

The first member of the family is the FF400R07A01E3_S6 implementing I _Cnom of 400A and V _CES of 700V in half-bridge configuration. Engineering samples will be available in September. The following month, the company will release a module implementing I _Cnom of 200A and V _CES of 700V in a full-bridge configuration.