Intermediate circuit with a first switch for switching a fuel cell stack and second switch for short-circuting the fuel stack, fuel cell system with an intermediate circuit, and method for controlling the intermediate circuit

摘要

An intermediate circuit for controlling the connection of a fuel cell stack to a load bus includes three switching elements arranged in a pi configuration. At least one such switching element is provided for short circuiting either or both of the fuel cell stack and the load bus, while a further switching element controllably interrupts the line connection between the fuel cell stack and the load bus. The respective switches are driven according to a control method that accommodates start-up operation, switch-off operation, emergency shut down, and a self diagnostic mode.