Circuit structure for improving short-circuit protection performance of large-sized battery pack by using capacitor

Abstract

The invention discloses a circuit structure for improving the short-circuit protection performance of a large-sized direct-current (DC) battery pack by using a capacitor. The circuit structure comprises the large-sized DC battery pack, a discharge field effect transistor (FET), a protection capacitor and a battery management system and is characterized in that the power positive pole of the large-sized DC battery pack is connected with a load, the power negative pole of the large-sized DC battery pack is in series connection with the discharge FET, the drain electrode of the discharge FET is connected with the large-sized DC battery pack, the source electrode of the discharge FET serves as the battery negative pole of the large-sized DC battery pack and is externally connected with the load, and the grid electrode of the discharge FET is connected with the battery management system which is used for monitoring the safety of a whole circuit; the protection capacitor is further parallelly connected between the drain electrode and source electrode of the discharge FET. According to the circuit structure, the loop inductive reactance of a short-circuited circuit is lowered through arranging the capacitor, and meanwhile, the time for the short-circuit protection of a whole circuit system is prolonged through storing current by the capacitor; the circuit arrangement is simple and convenient, so that not only is the short-circuit protection performance of the overall circuit not affected, but also the reliability and cost performance of the entire short-circuit protection circuit are improved.

Description

Technical field: [0001] The invention relates to the short-circuit protection of a large-scale battery pack, in particular to a circuit structure for improving the short-circuit protection performance of a large-scale direct-current battery pack by utilizing capacitance. Background technique: [0002] Large DC battery packs are known to draw very large currents when short-circuited. In order to protect the battery pack and the load, the battery management system is often required to disconnect the discharge circuit as soon as possible when a short circuit is detected. Generally, the required disconnection time is on the order of microseconds. However, due to the excessive current in the loop, when the high-speed disconnection occurs, the equivalent inductive reactance of components such as batteries, loads, and wires will generate a very high voltage on the switching device and the system, causing the switching device and system to fail. damage. [0003] Currently, there a...

AI Technical Summary

Problems solved by technology

[0004] 1. Improve the withstand voltage level of the switching device, the disadvantage is that the cost is increased and the circuit is complicated

[0005] 2. Use slower switching devices, such as relays, etc.

The disadvantage is that the response is not timely enough, the reliability is low, and it may cause other safety hazards

Images