Network Coordinated Power Point Tracking for Grid-Connected Photovoltaic Systems

摘要: Maximum power point tracking (MPPT) achieves maximum output for a photovoltaic (PV) system under various environmental conditions. It significantly improves the energy efficiency of specific PV system. However, when an increasing number systems are connected to distribution grid, MPPT poses several risks grid: 1) over-voltage problem, i.e., voltage in grid exceeds its rating; and 2) reverse power-flow that flows into allowed level. To solve these problems, all same distributed needs be coordinated via communication network. Thus, (CPPT) is studied this paper. First, optimization problem formulated determine points systems, subject constraints voltage, flow, fairness. Conditions obtain optimal solution then derived. Second, based on conditions, practical CPPT scheme developed. coordinates network, such that: flow maintained at normal level; each receives fair share surplus power. Third, wireless mesh network (WMN) designed support proper operation scheme. evaluated through simulations consider close interactions between WMN CPPT. Performance results show outperforms by gracefully avoiding both overvoltage problems; sharing among systems; 3) can reliably conducted WMN.