Novel dynamic voltage sharing device for serially connected super capacitor bank

Abstract

A novel dynamic voltage sharing device for a serially connected super capacitor banks comprises two parts including a hardware circuit and a controller, wherein the hardware circuit comprises a shunt capacitor Cb generating balanced current, a switch network, the super capacitor bank and a voltage measuring unit, the switch network comprises switches S1, S2, S3, S4, ..., S2n-1 and S2n, the super capacitor bank comprises super capacitors C1, C2, ..., Cn, the n is a natural number, and the voltage measuring unit comprises voltage measuring devices, and the number of the voltage measuring devices corresponds to the number of the super capacitors. Each group of the switches S2n-1 and S2n corresponds to the super capacitor Cn and the corresponding voltage measuring device thereof. Two poles of the shunt capacitor Cb are respectively connected two poles of the super capacitor Cn via the S2n-1 and S2n. The voltage UCn applied to the two ends of the super capacitor is measured by the corresponding voltage measuring device, and then measured result is transmitted to the controller. The controller outputs switch controlling signals to control switching conditions of the switches in the switch network.

Description

technical field [0001] The invention relates to the field of energy storage technology and power supply, in particular to a novel series-connected supercapacitor bank dynamic voltage equalization device and its control strategy, which are suitable for energy storage systems of electric vehicles, wind power generation and photovoltaic power generation. Background technique [0002] With the development of new energy power generation and electric vehicles, the importance of electrical energy storage has become increasingly prominent. Currently commonly used electric energy storage devices include: batteries, flywheels, supercapacitors, superconducting magnets, etc. As a new type of energy storage element, supercapacitors have superior performance, especially high power density, so they can be used as auxiliary energy sources, and batteries or fuel cells can be used as hybrid power sources for electric vehicles, which can well make up for traditional electric vehicles. The dow...

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Problems solved by technology

The flying capacitor voltage equalization method further reduces energy loss and reduces the repetitive and invalid energy flow caused by the existence of multiple capacitors in the switched capacitor method, thus speeding up the voltage equalization speed. However, in principle, it still relies on a The "flying capacitor" is used to transfer energy. Since the capacity of this capacitor is very different from that of the supercapacitor that needs voltage equalization, the voltage equalization process needs to go through a lot of switch network switching. On the one hand, it increases Switching loss, on the other hand, also increases the voltage equalization time, which is not suitable for dynamic voltage equalization occasions that require fast voltage equalization

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