Background: Since the first energy revolution, energy upgrades have always promoted industrial and social progress. It can be seen from the historical process of energy reform that as the marginal benefits of an energy with limited resources diminish, new energy is bound to gradually replace the old energy and alleviate the decline in the marginal benefits of the old energy. my country's new energy is developing very rapidly, with nuclear energy, wind energy, hydropower and photovoltaic power generation all developing rapidly. Among them, the annual output value of my country's photovoltaic industry is 300 billion yuan, making it the fastest growing new energy type in China. my country's photovoltaic power generation applications are mainly concentrated in large power stations and distributed power stations. With the implementation of the national "photovoltaic poverty alleviation" and electricity price policy adjustment strategies, it is foreseeable that the proportion of distributed power stations will increase in the future.  Introduction                                                      to the results: Off-grid inverter, the original version is used for aircraft secondary power supply static converters. The partner's products have passed the airworthiness certification of the Civil Aviation Administration of China and the third prize in AVIC Science and Technology Progress Award in 2011; it has parallel and three-phase combination application functions and has been mass-produced; it has been transformed into a photovoltaic off-grid system and can be further transformed into an inverter version for energy storage, fuel cells, railway signals, vehicles and other occasions; unique features: The input current ripple is small, and it can be combined into a three-phase system with inverters of the same specification from other suppliers. Obtained two authorized China invention patents. For grid-connected inverters, the 2.2kw and 3.3kw versions of the partner's products have passed Australian certification and have been finalized for mass production. Unique feature: Ultra-thin wall-mounted. The low-power photovoltaic micro-inverter has been transferred to the partner's research and development engineering prototype. Relevant technologies applied for 4 invention patents.

 Technical features: Household grid-connected inverters are added to energy storage devices to form off-grid photovoltaic inverters, which can carry out off-grid power generation work. Users can freely choose grid-connected or off-grid working modes according to the application situation. The energy of photovoltaic arrays is intermittent and is old before the grid. Inverters can improve their output stability and are also an important part of building a smart grid. The photovoltaic array, battery, load and power grid can be externally connected to the grid-connected photovoltaic inverter. The inverter system independently selects the working mode according to the power status of the external components, photovoltaic array and battery. The combination produces a wide variety of working modes, covering various usage needs of users. Such inverters can better leverage their multi-functional advantages in remote areas. Therefore, grid-connected photovoltaic inverters are more suitable for "photovoltaic poverty alleviation"., It can foresee its rapid development trend.