太阳能光伏辅助市电供电系统

以太阳能电池作为辅助电源，实现了与市电共同负载用电设备无蓄电不入网的直接供电方案。将太阳能电池组光伏输出经DC／DC变换器升压后的输出与用电设备的整流桥输出连接，并跟踪市电电压变化使之在相同的光伏条件下维持一定的输出功率；另外也设计了DC／DC／AC变换器电路逆变成与市电同频同相的交流输出，通过单向控制电路与市电隔离，使电源变换电路的输出只加载到用电设备中而不逆流进入到电力网，从而避免高昂的蓄电成本，或并网的输送、占地、维护等成本和入网的技术限制。

Assistant solar photovoltaic power supply with AC power grid

By using the solar cell as an assistant power source, the direct power supply to the electric equipments loaded together by the AC power is achieved without storing battery and input into the power grid. After DC/DC boost, the photovoltaic output from the solar cells is connected with the output ends of the rectifier bridge, while tracking the AC power variation to maintain a definite output power under a certain photovoltaic condition. Moreover, a DC DC AC inverter is designed to acquire the AC output consistent with AC power in frequency and phase. It output is connected to the electric equipment but separated from the AC power grid by the unidirectional controlling circuit to only load the equipment without inversely flow into the power grid. Thus the high cost of electricity storage, or power transportation, land occupying, maintenance as well as technical limitations of grid connection.