Method for optimizing and controlling dual-storage-battery hybrid energy storage system

Abstract

The invention relates to the technical field of hybrid energy storage system optimization control, and provides a method for optimizing and controlling a dual-storage-battery hybrid energy storage system. The method comprises the steps of: connecting two groups of storage batteries and a super capacitor to a photovoltaic array direct current bus to form a double-storage-battery hybrid energy storage system; connecting converters in the system with a controller; distributing the output power of the photovoltaic array through two stages of low-pass digital filters by a power distribution controlunit to obtain the output reference power of the photovoltaic array, the total reference power of the storage battery and the reference power of the super capacitor; and finally, dividing the total reference power of the storage battery into two portions by a double-storage-battery coordination control unit according to positive and negative, respectively distributing the two portions to the twogroups of storage batteries to enable the two groups of storage batteries to work in a charging and discharging state, and exchanging the working states of the two groups of storage batteries when thecharge states of the two groups of storage batteries reach a limit threshold value. The charging and discharging conversion times of the storage battery can be reduced, so that the service life of the storage battery is prolonged, and the situation that the hybrid energy storage system stops working due to over-discharge of the storage battery can be avoided.

Description

technical field [0001] The invention relates to the technical field of optimal control of a hybrid energy storage system, in particular to an optimal control method for a dual-battery hybrid energy storage system. Background technique [0002] Vigorously developing renewable energy is one of the effective ways to deal with the fossil energy crisis and environmental problems. Among them, photovoltaic power generation has developed rapidly in recent years due to its advantages of abundant resources and little influence by geographical location. Affected by fluctuations in the natural environment, the output power of photovoltaic power generation using the maximum power point tracking control method always fluctuates randomly. Large-scale photovoltaic grid-connection has brought many adverse effects on the actual operation of the power grid, which seriously limits the promotion and development of photovoltaics. [0003] The hybrid energy storage system is composed of energy-ty...

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Problems solved by technology

[0004] However, the randomness of photovoltaic output power leads to randomness in the output power of hybrid energy storage, which leads to the uncertainty of the working state of the battery in the hybrid energy storage, making the battery continuously change its charge and discharge state in a short period of time, affecting its use. life

In addition, the battery may continuously discharge to its maximum depth of discharge under uncontrolled conditions, which will not only cause the battery to stop working, affect photovoltaic grid-connected power generation, but also shorten the service life of the battery

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