Energy storage system formed by supercapacitor, lithium battery and lead-acid battery

Abstract

The invention relates to an energy storage system formed by a supercapacitor, a lithium battery and a lead-acid battery. The energy storage system includes a supercapacitor control branch, a lithium battery control branch, a lead-acid battery control branch and an energy storage battery intelligent control unit connected to each other in parallel. The supercapacitor control branch includes a firstswitch and a supercapacitor. The lithium battery control branch includes a lithium battery, a second switch and a first charging module connected in series. The lead-acid battery control branch includes a lead-acid battery, a third switch and a second charging module connected in series. The energy storage battery intelligent control unit samples the voltage of the supercapacitor, the voltage ofthe lithium battery, the voltage of the lead-acid battery, the output voltage and the collection current, and controls the on-off of the first switch, the second switch and the third switch, so as torealize the intelligent control of the energy storage battery system. Compared with the prior art, the energy storage system of the invention has the advantages of reducing the times of impulse and discharge, being prolonged in service life, balancing the power, reducing the power consumption cost of the battery, and the like.

Description

technical field [0001] The invention relates to the field of new energy storage, in particular to an energy storage battery system composed of a supercapacitor, a lithium battery and a lead-acid battery. Background technique [0002] As social progress pays more and more attention to environmental protection, solar power and wind power are widely used in distributed microgrid power generation systems. If there is an abnormality in the mains electricity, the normal operation of the electrical equipment can still be guaranteed. The microgrid is generally equipped with an energy storage device, which can also play a role in stabilizing fluctuations, peak shaving and valley filling, and energy scheduling. At present, small-capacity energy storage batteries are generally composed of lead-acid batteries, lithium batteries and supercapacitors. These three batteries have their own advantages and disadvantages. Generally, in traditional applications, lead-acid batteries and lithium ...

AI Technical Summary

Problems solved by technology

These three batteries have their own advantages and disadvantages. Generally, in traditional applications, lead-acid batteries and lithium batteries are used alone or in parallel with supercapacitors.

Among them, the biggest advantage of lead-acid batteries is that they are the cheapest, but they have the least number of charging cycles (500-1000 times), and there are memory effects when repeated shallow charging and discharging, which will reduce the effective storage capacity of the battery. The price of lithium batteries is in the middle. The number of cycle charging is about 5 times that of the battery, and there is no memory effect during shallow charge and discharge; the price of the super capacitor is the most expensive per unit capacity, but it has hundreds of thousands of cycle charging times

If the energy storage mode of the lead-acid battery is adopted, due to the discontinuity and interval of solar power generation and wind power generation, the lead-acid battery will be repeatedly charged shallowly, seriously affecting its service life

If the energy storage mode of lithium battery is adopted, the cost of the battery is high when the energy storage capacity is large. At present, the large-scale application of energy storage batteries faces technical and cost bottlenecks.

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