Fuel cell voltage monitoring system and the method thereof

摘要

This invention discloses a system and method for monitoring the voltage of a fuel cell in a fuel cell stack. The system comprises a plurality of differential amplifiers, a switching network, an analog to digital converter and a controller. The system may further include a remote PC. Each differential amplifier has a high common-mode rejection ratio. The differential amplifiers are connected to terminals in the fuel cell stack at which the voltage is to be measured. An output of a single differential amplifier is chosen by the switching network, under the direction of the controller, and converted to digital values by the analog to digital converter. The digital values are used by the controller to calculate the cell voltage of the fuel cell. The controller also controls the analog to digital converter. The invention further comprises a calibration method and apparatus which are used to calibrate the measurement system before performing voltage measurements on the fuel cell stack. This invention allows the cell voltage of a fuel cell with almost any common-mode voltage to be measured using readily available differential amplifiers.