Short-circuit current suppression circuit for flying capacitor converter and energy storage system with short-circuit current suppression circuit

Abstract

The invention discloses a flying capacitor converter and a short-circuit current suppression circuit and an energy storage system used for the flying capacitor converter. The flying capacitor converter comprises a controller, the high-voltage side of the flying capacitor converter being connected with a first power supply, the low-voltage side of the flying capacitor converter being connected with a second power supply. The short-circuit current suppression circuit comprises at least one current detection component connected to the low-voltage side and / or the high-voltage side of the flying capacitor converter; and at least a switch assembly, connected to the high-voltage side and / or the low-voltage side of the flying capacitor converter in series, and when the current detection component detects a short circuit condition, the controller controlling the switch assembly to disconnect the flying capacitor converter and the first power supply and / or the flying capacitor converter and the second power supply. According to the invention, the short-circuit current of the flying capacitor converter can be rapidly suppressed, the short-circuit capacity of the converter is reduced, and the short-circuit reliability of an energy storage system composed of a plurality of flying capacitor converters can be improved.

Description

technical field [0001] The present invention relates to a short-circuit current suppression circuit, in particular to a short-circuit current suppression circuit for a flying capacitor converter, a flying capacitor converter with the short-circuit current suppression circuit, and a flying capacitor converter with the energy storage system. Background technique [0002] At present, flying capacitor converters have begun to be used in energy storage systems, such as figure 1 As shown, multiple flying capacitor converters (such as figure 1 One end of converter #1, converter #2, ..., converter #n and other n converters) is connected to the DC grid or DC common bus, and the other end is connected to the energy storage element, such as super Capacitors or batteries (such as figure 1 There are n batteries such as Battery-1, Battery-2, ..., Battery-n shown in ). [0003] In practical applications, multiple flying capacitor converters are connected to the DC common bus to charge ...

AI Technical Summary

Problems solved by technology

[0005] (1) The diode D1 / D2 inside the faulty converter cannot cut off the short-circuit current from the energy storage element;

[0006] (2) Cause the short circuit of the DC common bus, cause the short circuit of other converters, and cause the failure of the whole system;

[0007] (3) The short-circuit current of other converters will flow to the short-circuit point of the short-circuit faulty converter #2. For example, when the short-circuit current of each converter is 100A, if 100 converters are connected in parallel, the total current flowing through the short-circuit point The short-circuit current is 10kA, and the excessive total short-circuit current will cause the fuse of the short-circuit faulty converter to be unable to be effectively disconnected;

[0008] (4) Excessive total short-circuit current will cause overheating damage to the mechanical parts of the short-circuited faulty converter;

[0009] (5) Excessive total short-circuit current will make it difficult to select a device that meets the short-circuit capacity when designing the converter, or must select a device with a large capacity, resulting in an increase in the cost of the converter;

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