Researsh On Household Photovoltaic Energy Storage Intergration Device And Control Strategy

With the rapid development of distributed photovoltaic power generation systems,clean and renewable photovoltaic energy has also been used in the construction of low-power residential photovoltaic power generation.However,the conditions of the external environment such as weather and temperature have a great impact on household photovoltaic power generation systems,making photovoltaic power output more intermittent and fluctuating,especially in the less developed and remote areas in the west.The deployment of energy storage devices in residential photovoltaic power generation systems is an advantageous way to suppress the fluctuation of photovoltaic output power,promote the local consumption of photovoltaic energy,and improve the efficiency of photovoltaic power generation,laying a foundation for the widespread promotion of residential photovoltaic power generation systems in the future.This paper researchs on the design and control strategy of the household photovoltaic energy storage integration device.The overall system integrates household photovoltaic arrays,power converters,and battery energy storage devices into one,which is easy to install,operate and use;and if the existing photovoltaic power generation system is used,access to the designed energy storage system and control strategy,also can achieve the goal of coordinated and orderly operation of optical storage integrated devices.The core of operation is that the photovoltaic array provides the required energy for the load,and the excess or insufficient energy is dynamically adjusted through the charge and discharge of the battery.The main work done in this article is as follows:(1)Firstly,the structure of the household photovoltaic energy storage integration system is analyzed,and the overall structure of the energy storage device connected from the DC side is selected through comparative analysis.In the overall household optical storage integrated device,photovoltaic arrays,inverters and rectifiers are finished products that are selected based on system index parameters.The main research focus is on the design of the energy storage system and the energy storage in the system.The choice of battery is a hybrid battery pack composed of both energy-density and power-density lead-acid batteries.In the design of the internal topology of the energy storage device,two types of energy storage batteries are connected to the bidirectional DC/DC and then connected in parallel on the DC bus side.After the system structure is determined,the principle analysis and introduction of each component are carried out.(2)Secondly,optimize the capacity of residential photovoltaic cells and energy storage batteries.Taking the load power consumption situation of a household in a remote area in the northwest as an example,the historical installed photovoltaic data is used to calculate the installed capacity of residential photovoltaics equivalently.Under the premise of fixed photovoltaic capacity,combined with the storage capacity life decay,the hybrid energy storage cost is optimized.Economic model.Because the model objective function is complex and there are many constraints,the multi-objective algorithm combined with particle swarm optimization algorithm is used to calculate the optimal ratio and capacity of mixed energy storage.(3)Nextly,based on the characteristics of the hybrid energy storage system and the two types of batteries,a charge and discharge control strategy for the hybrid energy storage battery is designed.The power division method of the low-pass filter is adopted for the net power allocation that the hybrid energy storage system needs to absorb or release.Energy type batteries mainly bear low frequency power,power type batteries bear high frequency power and auxiliary energy type batteries.In order to prolong the service life of energy storage batteries,control strategies for hybrid energy storage and constraints on battery characteristics and optimization of battery protection have been added.With the change of external conditions,in order to coordinate the stable operation of the system,various modes of system operation and corresponding energy management control strategies were analyzed and designed.A system model of a household optical storage integrated device was built in MATLAB/simulink to simulate the system.verification.(4)Finally,the overall hardware and software implementation scheme of the system is designed.The hardware design part mainly includes the design of the main circuit,the drive circuit,the sampling circuit,and the protection circuit,and the selection of related devices.The software design part mainly writes the main program,interrupt subroutine,charge and discharge control,and energy management subroutine.An experimental platform based on the STM32F1x series controller was set up.The designed hybrid energy storage device was verified and the experimental results were analyzed to prove the feasibility and rationality of the designed control strategy.