Fuel Cell Startup Control via Parallel BHDC Boosting

The patent applies preliminary action by pre-charging the low-voltage battery before the startup sequence begins. The battery is charged during vehicle operation or idle periods, so when startup is needed, the voltage boost is already available immediately, eliminating the sequential delay of charging the battery first before proceeding with other startup steps.

The patent merges multiple sequential operations into a parallel execution model. Specifically, the BHDC boosting operation and the air compressor operation are performed simultaneously using the pre-charged low-voltage battery, rather than waiting for one to complete before starting the other. This parallelization dramatically reduces the overall startup time while maintaining system reliability.

The patent applies preliminary action by pre-mixing hydrogen and air in the manifold before the fuel cell stack is activated. The recirculation blower circulates and mixes the gases in advance, so when the stack becomes operational, the mixture is already prepared and can immediately begin generating power without exposing the stack to open circuit voltage conditions.

The patent skips the problematic intermediate state where the stack would be exposed to open circuit voltage. By pre-mixing the hydrogen and air outside the stack and then rapidly introducing the mixture when the stack is ready, the system rushes through the critical transition period, eliminating the durability-damaging OCV exposure phase entirely.