AC-DC power supply DC side short circuit protection circuit, method and chip

Abstract

The invention discloses an AC-DC power supply direct current side short circuit protection circuit, method and chip, the circuit comprises a bidirectional protection switch unit and an AC-DC power supply internal circuit, the bidirectional protection switch unit is arranged on an AC-DC power supply external direct current bus, the bidirectional protection switch unit is connected with the AC-DC power supply internal circuit, and the bidirectional protection switch unit is connected with the AC-DC power supply external direct current bus. The AC-DC power supply internal circuit comprises a rectification unit and a filtering unit, and the rectification unit is connected with the bidirectional protection switch unit and the filtering unit. The first electronic switch and the second electronic switch are additionally arranged at the output port of the direct-current bus of the power supply to introduce a brand new bidirectional protection switch, so that the bidirectional protection function of the power supply circuit is realized, the number of added devices is small, the cost is low, the application range is wide, the influence on the efficiency of the whole machine is small, the protection action is fast, the reliability is high, and the practicability is strong; and the power device can be quickly and effectively protected under extreme conditions.

Description

technical field [0001] The invention relates to the technical field of power supply protection circuits, in particular to a short-circuit protection circuit, method and chip of a DC side of an AC-DC power supply. Background technique [0002] In the production process of lithium batteries, the power consumption is huge, and energy saving and consumption reduction are very urgent to improve the efficiency of battery manufacturers. At present, the production of lithium batteries adopts a distributed / discrete power supply mode. During the process of dividing the capacity of lithium batteries, the energy of battery charging and discharging should be concentrated to the AC mains power supply terminal of the common node for neutralization and offset. This process removes the same constant current source at the battery terminal. In addition to the DC / DC link, there are two conversion links, DC / DC and DC / AC, at the front stage, and the power loss is relatively large. If the energy ...

AI Technical Summary

Problems solved by technology

However, in the topology scheme provided by the existing technology, once the external DC bus is short-circuited, the current will flow uncontrollably from the AC input terminal through the AC / DC IGBT anti-parallel diode, and there is a high probability that the PCS will fail.

Moreover, the protection components commonly used in the existing technical solutions are insurance or circuit breakers, and the fusing characteristics of the insurance often cannot match the diode characteristics of the AC / DC power supply. The insurance cannot be fused in time and effectively, and timely and effective protection functions cannot be realized; The action time is at the millisecond level, which is much longer than the microsecond level protection requirements for power semiconductors

[0004] To sum up, the configuration of the current three-phase high-frequency rectification / inversion scheme cannot effectively realize the short-circuit protection function, and there is a high probability of explosion risk when the DC terminal is short-circuited

In addition, protecting the power supply through insurance is at the cost of sacrificing the failure of the insurance itself, which does not meet the basic functional requirements of high practicability of power supply products

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