Cascading multi-level super capacitor energy storage system and discharge mode control method

Abstract

The invention discloses a cascading multi-level super capacitor energy storage system and a discharge mode control method. The system comprises at least two half-bridge converters, super capacitor energy storage units, an LC series circuit, a voltage detection unit and a controller, wherein the input end of each half-bridge converter is connected with one super capacitor energy storage unit in parallel, the half-bridge converters are connected between the anode and the cathode of a common direct current bus in a cascading manner, the LC series circuit is connected between the positive terminal of the output end of the first half-bridge converter and the negative terminal of the output end of the last half-bridge converter in parallel, the voltage detection unit is used for transmitting the end voltage of anode of the common direct current bus and end voltages of super capacitors to the controller, the controller is used for controlling each half-bridge converter to output a direct current power component and output/input a high-frequency alternating current component, the direct current power components are supplied to a load through the common direct current bus, and the high-frequency alternating current components flow between the cascading half-bridge converters and the LC series circuit for balancing energy of the super capacitors.

Description

technical field [0001] The invention relates to the technical field of energy storage, in particular to a cascaded multilevel supercapacitor energy storage system and a discharge mode control method. Background technique [0002] Supercapacitor is a new type of energy storage device with high energy density. It has the advantages of high power density of conventional capacitors and high specific energy of rechargeable batteries. It can be charged and discharged quickly and has a long life. It is used in electric vehicles, emergency power supplies and power automation equipment It has a good application prospect. [0003] The voltage of a single supercapacitor is low, generally not exceeding 2.7V. In order to meet the needs of the voltage level, a plurality of single supercapacitors are usually connected in series to form a supercapacitor energy storage unit, and then connected in parallel with a power conversion circuit to form an energy storage unit. system to obtain a sta...

AI Technical Summary

Problems solved by technology

However, this method requires multiple charge and discharge cycles to achieve energy balance, and it is not effective for DC / DC conversion mode and island inverter mode.

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