With the development of solar optoelectronics industry, a grid-connected hybrid power supply system that can comprehensively utilize solar photovoltaic module arrays, mains power and backup oil generators has emerged. This kind of system is usually integrated with the controller and inverter, using computer chips to fully control the operation of the entire system, comprehensively utilizing various energy sources to achieve the best working condition, and using batteries to further improve the load power supply guarantee rate of the system , such as AES’s SMD inverter system. The system can provide qualified power for local loads and can work as an online UPS (uninterruptible power supply). It is also possible to supply power to or obtain power from the grid. The system usually works in parallel with the mains power and solar power. For local loads, if the power generated by the photovoltaic modules is sufficient for the load, it will directly use the power generated by the photovoltaic modules to supply the load. If the electricity generated by the photovoltaic modules exceeds the demand of the immediate load, the excess electricity can be returned to the grid; if the electricity generated by the photovoltaic modules is not enough, the utility power will be automatically enabled to use the utility power to supply the needs of the local load, and, when the local When the power consumption of the load is less than 60% of the rated mains capacity of the SMD inverter, the mains will automatically charge the battery to ensure that the battery is in a floating charge state for a long time; if the mains fails, that is, the mains fails or the mains If the quality of the load is not up to standard, the system will automatically disconnect the mains and switch to an independent working mode, and the AC power required by the load is provided by the battery and the inverter. Once the mains power returns to normal, that is, the voltage and frequency return to the above-mentioned normal state, the system will disconnect the battery and work in grid-connected mode, powered by the mains. In some grid-connected hybrid power supply systems, the system monitoring, control and data acquisition functions can also be integrated in the control chip. The core components of this system are the controller and inverter.