Abstract: The present disclosure relates to a risk early warning method and system for hydrogen leakage, and relates to the field of hydrogen leakage. The method includes: obtaining ventilation information of a hydrogen-related area; carrying out grid division on a pipeline system of the hydrogen-related area to obtain a gridded pipeline system; determining a risk coefficient corresponding to each grid of the gridded pipeline system according to leakage sources of the pipeline system; determining a high-risk region by means of a jet cone model according to the risk coefficients; determining a medium-risk region, a low-risk region and a safe region according to the risk coefficients and the ventilation information; and carrying out risk early warning according to the high-risk region, the medium-risk region, the low-risk region and the safe region.

Abstract: The present disclosure relates to a risk early warning method and system for hydrogen leakage, and relates to the field of hydrogen leakage. The method includes: obtaining ventilation information of a hydrogen-related area; carrying out grid division on a pipeline system of the hydrogen-related area to obtain a gridded pipeline system; determining a risk coefficient corresponding to each grid of the gridded pipeline system according to leakage sources of the pipeline system; determining a high-risk region by means of a jet cone model according to the risk coefficients; determining a medium-risk region, a low-risk region and a safe region according to the risk coefficients and the ventilation information; and carrying out risk early warning according to the high-risk region, the medium-risk region, the low-risk region and the safe region.

Abstract: The present invention relates to a rapid low-temperature self-heating method and device for a battery. Active controllable large-current lossless short-circuit self-heating cooperates with an external heater to implement rapid composite heating, so that a battery is rapidly heated in a low-temperature environment and is controlled to fall within an optimal working temperature interval, so as to improve energy utilization of the battery and durability of a battery system. Before the battery system is started, battery temperature is first determined; when the temperature is less than a threshold, an external short-circuit is first proactively triggered to generate a large current to implement self-heating inside the battery. The method is simple, easy to implement, and safe and reliable, and can effectively resolve a problem that an electric vehicle has large capacity degradation and poor working performance in a low-temperature severe cold working condition.

Abstract: The present invention relates to a rapid low-temperature self-heating method and device for a battery. Active controllable large-current lossless short-circuit self-heating cooperates with an external heater to implement rapid composite heating, so that a battery is rapidly heated in a low-temperature environment and is controlled to fall within an optimal working temperature interval, so as to improve energy utilization of the battery and durability of a battery system. Before the battery system is started, battery temperature is first determined; when the temperature is less than a threshold, an external short-circuit is first proactively triggered to generate a large current to implement self-heating inside the battery. A method for determining a large-current lossless short-circuit time threshold is disclosed.