Research On Distributed Solar Photovoltaic Intelligent Power System For Rural Households

With the continuous development of the economy and society,my country’s dependence on energy has gradually increased,the use and demand of energy have continued to grow,and the burning of a large number of fossil fuels has led to frequent occurrence of haze during the heating season.The achievement of “carbon neutrality” may completely realize the solar energy era within 40 years.The characteristics of clean,safe and huge development potential of solar energy indicate that solar energy will become the world’s largest energy source.At present,most of the electric energy generated by photovoltaic power generation systems cannot be consumed locally,but only limited to lighting and power supply for household appliances,resulting in a serious shortage of on-site consumption capacity of photovoltaic power generation,which greatly limits and seriously affects the sustainable and healthy development of photovoltaic power generation.At the same time,in the winter in northern China,where solar energy resources are abundant,coal-fired heating causes environmental pollution and smog.Looking for cleaner energy,reducing energy consumption during transportation,and achieving self-sufficiency in heating for users has become a new trend in heating.Therefore,the combination of distributed photovoltaic power generation and heating systems can not only reduce haze while meeting heating requirements,but also promote the on-site absorption of photovoltaic power generation.In addition,summer air conditioning and annual domestic hot water are also an important part of people’s quality of life,but the combination and control strategy in the distributed photovoltaic power generation household power system has not been discussed yet.Therefore,this article proposes a distributed solar photovoltaic intelligent power system that can meet the needs of household lighting,electrical appliances,summer air conditioning,winter heating,and year-round domestic hot water,which will help greatly promote the local consumption of photovoltaic power.Ability while improving people’s quality of life.The household distributed photovoltaic intelligent power system,including photovoltaic power generation systems,air source heat pump systems,indoor heating and cooling terminal systems,solar collectors,hot water storage tanks,household appliances,etc.The photovoltaic power generation system mainly includes photovoltaic panels,inverters,charge and discharge controllers and other equipment.The photovoltaic system generates electricity for household electricity and is connected to the national grid.The air source heat pump system is used as the cold and heat source for heating and cooling.The heating terminal in winter adopts low-temperature hot water ground radiation heating,and the cooling terminal in summer adopts a fan coil system to ensure heating in winter and cooling in summer.Solar collectors choose vacuum tube solar collectors to provide hot water for domestic use throughout the year.Two water tanks,a heating water tank and a living water tank,are provided to store hot water separately.The control system consists of two sub-systems,one is to control the opening of the solenoid valves in the domestic water tank and the hot water supply tank,and the other is to control the source of household electricity,whether the electricity comes from the national grid or from photovoltaic power generation.In order to investigate the acceptance of the system,a questionnaire survey was conducted in Guozhuang Village,Mashan Town,Changqing District,Jinan City,to understand the income of villagers,the installation of household photovoltaic power generation,the understanding of air source heat pump systems,and the promotion of distributed solar photovoltaic intelligence Willingness to use electricity system.The survey results show that reducing investment expenditures makes more villagers more willing to accept the system.A residential photovoltaic power generation system with a building area of 105.6m2 is selected in a rural area of Jinan,and the annual power generation is simulated and calculated to obtain the photovoltaic power generation in the transition season,heating season,and cooling season.The total annual power generation is 8148 k W·h.Using De ST software to simulate the building’s annual cooling and heating load,the annual cumulative heating load is 7726 k W·h,and the cooling load is 3323.43 k W · h.For the equipment selection in the system,determine the equipment models of the air source heat pump,the end of the indoor refrigeration and heating system,the solar collector,the living water tank and the hot water supply tank.Using TRNSYS software to simulate the annual power consumption of the air source heat pump,the peak and valley time-sharing power consumption in the heating and cooling seasons is obtained.The annual power consumption in the heating season is 1836.9k W·h,and the peak power consumption is 785.8k W· h,the power consumption at the trough stage is 1051.1k W·h.The power consumption during the cooling season is 1108.7k W·h,of which the power consumption in the peak phase is 936.8k W·h,and the power consumption in the trough phase is171.9k W·h.The annual power consumption of other household appliances in the building is2518.5k W·h,and the total annual power consumption is 5464.1k W·h.The photovoltaic power generation can meet the annual electricity consumption of buildings in the peak section,and all the power in the valley section comes from the national grid.Based on the economic analysis of the system,the initial investment of the distributed solar photovoltaic intelligent power system was 38,738 yuan,and the remaining power of the system connected to the State Grid could make a profit of 3997.1 yuan;the valley section consumed a total of 795.3 yuan for the whole year,and made a total profit for the whole year.3201.8 yuan,the project payback period is 4.5 years.It can reduce the burning of 1.512 tons of coal,3.11 kg of smoke and dust,17.88 kg of sulfur dioxide,9.52 t of carbon dioxide,and 13.52 kg of nitrogen oxides throughout the year.The household distributed photovoltaic intelligent power system provides solutions to better solve the problems of rural heating in winter,cooling in summer,annual electricity and domestic hot water,and improves the happiness of rural residents.Bring great economic and environmental benefits,and has the value of promotion and application.