Photovoltaic Power Station Monitoring System Research And Development

In recent years, China’s PV industry has developed rapidly in some areas. Variousphotovoltaic power stations operate alone, each small-scale photovoltaic power stationis equipped with its own technical operation and management personnel and lack ofeffective coordination and scheduling and monitoring between the power plants.Consequently, the cluster control of a number of small-scale photovoltaic power plantsis the urgent problem at present. Thus, in December2011,"Research and developmentof cluster control system on wind farms and photovoltaic power stations" projectofficially included in the national863project.The paper analyzes the three-tier system control structure of the photovoltaicpower generation, including main controlling layer, production, and local control unitslayer. Based on the application of large-scale photovoltaic power station, photovoltaicpower plant remote monitoring control system is designed in MODEM dial-up way tosolve the remote monitoring problem in photovoltaic power plant. The researchcontents are list as follows:First, regard the issue of the maximum power point to the short-circuit currenttracking method, no load voltage tracking method. Incremental power point tracking ofphotovaltaic power generation by variable step length disturbance observation methodis propose. The state of PV cell array and disturbance observer method have beenimproved and simulated.Second, the inverter of photovoltaic power plant is studied. Analyses of thecurrent frequently used two-level inverter structure are given, and the inverter based onthe FL494and SG3926is designed.Third, the IG-NT power plant monitoring module is employed to acquire thepower plant parameters, communicate and transfer data between PC, control the PVgrid-connected inverter, and indirectly and the maximum power point tracking isachieved. Multi-photovoltaic power station monitoring network is designed by IG-NT as slave controller.Fourth, a MODEM dial-up photovoltaic power station remote monitoring basedon W77E58MCU is built. The IGS-NT series station monitoring module are taken asthe main controller, to monitor the relevant parameters of photovoltaic cells andcontrol circuit breaker and the inverter at the same time. The monitoring is achievedthrough the main control cabinet, the circuit breaker cabinet, and the remote controlcabinet.Finally, based on the design of each part of photovoltaic power generationsystem, an effective management system cluster is built and, the PV power plant activepower distribution system are designed to solve the allocation problems of the PVpower plant active power.