Research on China's First Residential Grid-Connected Photovoltaic System

Along with the continuous expansion of photovoltaic (PV) power generation, different capacity of grid connected PV system is gradually increased. China's first residential grid-connected PV system has interconnected successfully in QingDao and operated normally. This document analyzed electrical connected diagram of grid-connected PV system. Using power quality analyzer, the online power quality is monitored and analyzed. When PV power generation is low efficiency of operating state, harmonic current is over distortion limits. Monitoring data was simulated through electrical power standard source. To ensure power metering accuracy under harmonic, the watt-second method is proposed. Testing results show that smart electrical meter can meter accurately within 20 times harmonics.