The Development Of Grid Inverte For The Efficient Micro Photovoltaic

This paper aims to study the main steps that transfer battery from the solar panels to electricity grid. The unstable low voltage DC generated by the solar panel is first charged the battery according to PV-MPPT-Charger. And then the low voltage DC of battery is transferred to the stable high voltage DC adopting LLC-boost converter. Finally, high voltage DC is generated the AC current with the same frequency and phase from the grid based on the Full bridge inverter.Note that there is some difference between high-efficiency gird-connected PV inverter and traditional grid-connected PV inverter. The traditional grid-connected PV inverter not considers the Energy-Storage part. Distinct from them, the proposed system charge to battery from the PV-MPPT-Charger. In addition, the charging management function is another advantage for our system, it can protect battery in the normal operating conditions.There are two advantages for the charging management part. On the one hand, it can maintain continuity of grid-connected for lack of sun. On the other hand, PV-MPPT-Charger is more fit for homes and buildingsThis paper adopts the full-bridge LLC resonant technique to study the DC-DC boost part. Because the LLC resonant technique have the feature which can made MOSFET zero Voltage switching MOSFET. We applied the DC-DC boost part to improve the effective of Grid-connected system, in order to achieve the technical requirements of Energy Conservation&Emission ReductionThis paper adopts the full bridge inverter circuit and LCL filter circuit in the DC-AC inverter. Based on the rapid process of DSP, this paper introduces the Digital Phase-Locked Loop Technology (DPLL) instead of Zero Phase-locked Loop Technology in the control system. It provides the hardware and software support for Grid-connected.There is perfect system protection mechanisms for PV-MPPT-Charger. The PV-MPPT-Charger have the properties of the charging management function. It is an advantage that Input under voltage protection function and Over Current Protection function for The full-bridge LLC converter. We have shown that the DC-AC inverters have Over Current Protection function and protecting battery functioned.Finally, this paper analyses the principle and the parameters of three components of PV-MPPT-Charger, and implements the basic function of each step. Finally we have shown that the effective of our system by debugging verified.Experiment proves that the PV-MPPT-Charger have high work stability and work efficiency. In addition, it provides the conditions for the Low-Voltage Direct Current electricity system for homes and builds. Hence, this paper has broad application prospects.