Working method of a system with a direct current liquid chiller in a low temperature and low pressure state

Abstract

The application discloses a working method of a system with a direct-current liquid cooling machine in a low-temperature and low-pressure state, and comprises the following steps: collecting system operation parameters in real time by a BMS; determining the current working condition type of the system according to the system operation parameters and external states; controlling the on-off state of a relay according to the working condition type, and establishing a high-voltage power supply circuit of the liquid cooling machine; executing a pre-charging process under a low-temperature working condition, disconnecting a K2 total negative relay after the pre-charging is completed, maintaining the conduction of a power compensation relay, and switching the liquid cooling machine to external power supply; continuously monitoring the lowest battery cell temperature, and closing the K2 total negative relay when the lowest battery cell temperature is higher than a set temperature threshold value, and entering a normal charging process. The application distinguishes six working conditions, i.e., standby, external discharge, normal-temperature external discharge, normal-temperature alternating-current power compensation, low-temperature direct-current power compensation and low-temperature alternating-current power compensation, one set of hardware topology covers all working scenes, and the pain point that the low-temperature and low-pressure coexisting working condition cannot be preheated and compensated is solved completely.

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